ML20028F525
| ML20028F525 | |
| Person / Time | |
|---|---|
| Site: | Satsop |
| Issue date: | 01/26/1983 |
| From: | Bouchey G WASHINGTON PUBLIC POWER SUPPLY SYSTEM |
| To: | Knighton G Office of Nuclear Reactor Regulation |
| References | |
| GO3-83-73, NUDOCS 8302020068 | |
| Download: ML20028F525 (97) | |
Text
{{#Wiki_filter:c Washington Public Power Supply System P.O. Box 968 3000GeorgeWashingtonWay Richland, Washington 99352 (509)372-5000 January 26, 1983 G03-83-73 Docket No. 50-508 Director of Nuclear Reactor Regulation Attention: George W. Knighton, Chief Licensing Branch No. 3 Division of Licensing U. S. Nuclear Regulatory Commission Washington, D. C. 20555
Subject:
SUPPLY SYSTEM NUCLEAR PROJECT N0. 3 ENVIRONMENTAL REPORT - OPERATING LICENSE STAGE RESPONSE TO NRC REQUEST FOR INFORMATION
Reference:
Letter, GW Knighton (NRC), to RL Ferguson (Supply System), dated Decemt'er 15, 1982 A request for information resulting from the Environmental Engineering Branch review of the WNP-3 ER-0L.was transmitted under the referenced letter. Please find the Supply System's response attached. If you require additional information or clarification, please contact KW Cook, Licensing Project Manager at WNP-3 (206/482-4428 Ext: 5436). Very truly yours,
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G. D. Bouchey, Ma ager Nuclear Safety & Regulatory Programs JPC/sm Attachment cc: WG Albert NRC D Smithpeter BPA 762 A Vietti NRC 0 001 8302020068 830126 PDR ADOCK 05000508 C PDR
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, .. . e ATTACHMENT RESPONSES TO NRC QUESTIONS OF D2CEMBER 15, 1982 (Re: WNP-3 ER-OL) me.
WNP-3 ER-OL 290.03 Q. Provide updated information (1981-1982) on any sightings of bald eagles or peregrine falcons on site or in the immedi-ate site vicinity (i.e., within two miles). Identify any bald eagle rest sites in the site vicinity. A. One or two bald eagles were observed from February through September 1981 under the Supply System's environmental monitoring program and four eagles were observed by tha Washington Department of Game in April 1981. No bald eagle sightings were docu- mented near the site in 1982 (Letter, K. R. McCalister, Wash. Dept. of Game, to T.' B. Stables, Supply System, dated January 18,1983). No active eagle nests were noted during the four years-(1979 through 1981) of Supply System surveys or reported to tne Department of Game in 1982. Peregrine falcons have not been observed through 1982 (Supply System surveys and communication with Dept. of Game). 290.04 Q. What vegetative type will be maintained on the clearcut area immediately north of the plant during the life of the plant? A. Many of the facilities (e.g., parking lots, warehouses, service buildings) in the area immediately north of the plant will be maintained to support plant operation. Many areas .1 orth of the Plant Connecting Road (Figure 2.1-1) and east of the warehouses (Figure 3.1-1) have been planted with a grass seed mixture and have established interspersed stands of alder. It is planned that other areas north of the plant not required for operation (principally laydown areas), will be planted to a grass cover. 290.05 Q. Provide information on the plant species used to revegetate areas along the east, west and Ranney well access roads. What native species will be used to revegetate disturbed areas? Identify disturbed areas that will require revega-tion. A. Areas disturbed by construction of the east, west and Ranney well access roads were promptly seeded for erosion control. Areas planted in 1977, including the east access road, were seeded with a mixture of English perennial rye-grass (20-25 lbs/ac). The west access road and Ranney well access road were seeded and the east access road was re-seeded in 1978 with a mixture of Astor perennial ryegrass
. (3 lbs/ac), Illahee creeping red fescue (6 lbs/ac), Marsh-field big trefoil (4 lbs/ac), and climax timothy (2 lbs/ac) or either Alta or tall fescue (10 lbs/ac).
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WNP-3 ER-OL l l All areas disturbed by Supply System activities are seeded with the above mixture as soon as possible after. construc- l tion activities cease and the area is not required for ' plant operations. Experience at the site has shown that indigenous species, principally Red alder, will become es-tablished in the grassed areas in a short period. Areas suited for timber production, notably the 80-acre Cooley laydown, may be replanted with Douglas fir. The Supply System is presently developing a wildlife habi-tat mitigation plan with the Energy Facility Site Evalua-tion Council. Areas addressed by the plan may include lay-down yards, sedimentation ponds, borrow and fill areas, and the Ranney well field. Several selected areas may'be planted with native species (such as Douglas fir, Western red cedar, Black cottonwood, Pacific willow, Snowberry, and Spiraea) suited for wildlife habitat. 290.06 Q. The statement is made (Sec. 5.1.4.2), " Deposition rates within 500 feet of the tower are quite uncertain, but be-yond this distance, maxim 4m total ceposition is expected to be below about 20 lb/ acre-yr." This deposition is contra-dictory to a value of 2 lb/ acre-yr shown in Figure 5.1.4. Please clarify. A. The text and Figure 5.1.4 were consist 9nt; a small area within the 2 lb/ acre-yr isopleth could have deposition rates of 20 lb/ acre-yr. The drift deposition estimates were revised by Amendment 1 (December 1982). 290.07 Q. Provide any site planning documents on crosion control, vegetat.an management and wildlife management. A. Erosion control planning for the site was commenced early in'the design of the plant and site layout. The principal planning documents include numerous design dran:ings and i revisions to drawings. The initial plans were described in Subsection 4.l.2.1 of the ER-CP as noted on Page 4.0-1 of L the Ef.-0L. Modifications of the erosion control system in l-response to severe rainfall events are also noted on Page 4.0-1. Modifications continue to be effected as construc-tion proceeds (e.g., an area is stabi,lized with vegetation, therefore a pump station is removed). There are no contemporaneous planning documents addressing
. erosion control, vegetation management, and wildlife man-agement. The wildlife habitat mitigation plan noted in response to Q290.05 is in development and will be relevant to all three areas.
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WHP-3 ER-OL 291.19 Q. Provide a listing (re: Section 2.2.2.8) of any species listed as threatened or endangered by the State of Washing-ton in the Chehalis River, the several tributary creeks surrounding the WNP-3 site, the Wynoochee River, and the Satsop River. A. The State of Washington has not established a list of threatened or endangered aquatic species separate from federal listings (Personal Communication, T. B.-Stables, Supply System, with K. McCalister, Wash. Dept. of Game, January 14,1983). - 291.20 Q. Provide a bibliographic listing and reprint copies of all journal and professional conference proceedings publica-tions (by applicant and his consultants) that have resulted from studies and monitoring of the WNP-3 site and vicinity. A. The following papers relating to environmental aspects of the construction or operation of WNP-3 have been included in professional conference proceedings. Jeane II, G.S.,-L. L. King, and K. R. Wise, " Erosion Con-trol at WPPSS Nuclear Projects Nos. 3 and 5," In: Proceed-ings of Conference X of the International Erosion Control Association, Seattle, Washington, March 1 & 2, 1979. Copp, H. D., N. S. Shashidhara, and K. R. Wise, " Hydraulic Modeling of Thermal Discharges into Shallow Tidal Affected Streams," In: Proceedings of the Third Conference on Waste Heat Management and Utilization, Miami, Florida (Not published). Copp, H. D. and N. S. Shashidhara, " Thermal-Hydraulic Mod-
- l. eling of Buoyant Effluent Dispersion in Shallow Streams,"
In: Congress XIX of the International Association for Hydraulic Research, New Delhi, India, 1981. l Chu, A., " Preview of Toxics Control - A Case Study on Cop- ! per," presented at: Edison Electric Institute /Envirosphere l Conference on Environmental Licensing and Regulatory Re-t quirements Affecting the Electric Utility Industry, New York, New York, October 21-24, 1979. Kenny, J. H., and K. R. Wise, " Underground Water Intake for Nuclear Plant Will Protect the Environment," conference.and
, date not recalled.
A copy of each of these papers is attached to the original of this submittal. l f l l l
WNP-3 ER-OL 291.21 Q. In the NRC ASLB Decision of April 8, 1977, 5 NRC 964 (1977), Finding No. 47 states: "The Applicant has made provisions for mitigating adverse impacts associated with this con-sumptive use (of Chehalis River water) by purchasing re-leases of 62 cfs of flow from the Wynocchee Reservoir to supplement the Chehalis River during low flow periods." (1) Provide an update on the status of this mitigation plan. (2) Provide an analysis of the environmental ef-fects of removing 62 cfs of water from Wynoochee Reservoir during low-flow periods. A. The Wynoochee Reservoir was constructed to augment the City of Aberdeen's industrial water supply system. The City has had industrial water supply facilities for many years in-cluding a diversion dam at River Mile 8 on the Wynoochee and a 100-cfs capacity delivery system. The watershed could meet such a demand without storage although the riverbed was dried up on occassion below the diversion dam. In the hope of attracting new industry to the Grays Harbor area, Wynoochee Dam was constructed to provide an additional 200 cfs firm supply plus a 50 cfs minimum flow in the lower river. The City has existing water rights to withdraw a full 300 cfs though none of the additional capability had been purchased until the Supply System's recognition of a potential mitigation measure. The Supply System has completed a contract with the City of Aberdeen for 62 cfs of water from the Wynoochee industrial supply. The water is to remain in the Wynocchee and will preclude reduction of Wynoochee River flows below 112 cfs. The reservoir drawdown remains within that contemplated for normal operation of the reservoir. There are no perceive-able negative environmental effects from this mitigation purchase. Positive effects should be realized in the lower Wynoochee with the increased minimum stream flows.
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EROSION CONTROL DdLLAR: Wasted Or Save'd? . l .
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Proceedings ofConference X International Erosion Control Association March 1 & 2,1979 - at The Red Lion Inn Seattle, Washington , l ! .-.a;.:g g _ ,__,._ _ _.,____- _ _. _ _;
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y-. - _ - . } l I CONTENTS
' PRACTICAL REGION,USDA EROSION CONTROL FO, REST SERVICE APPLICA'ITONS IN T RaymondV. Adolphson . . 3 EROSION ANDTHE SEDIMEhT CONTROL - AN OPERATION CENTRALIA COAL MINE R.A. Hickey and].C. Wisch . . . '11 EROSION CONTROL AT WPPSS NUCLEAR PROJECTS N G.S.Jeanne II, L.L. King, andK.R. Wise . . 21 FIBERS WHAT'S NEW?
. BurgessL. Kay . . 33 HYDRAULIC SEEDING IS NOT THE ONLY WAY BurgessL. Kay . . 40 THE HIGH COST OF CONTROLLING EROSION Norman M. Krisburg . . 48 i
IMPROPER SPECIFICATIONS CAN WASTE DOLLARS JackMcWharter . . 31 SAVED OR WASTED DuaneL.Nelsoz . . . J3 REVEGETATION EFFORTS ON THE MT. HOOD NATION RobertPosey andJack Parcell . . . J7 SECOND -YEAR RESULTS OF THE CHENA RIVER LA REVEGETATION PROJECT DavidA. Gaskin, LawrenceJohnson, andSusan D. Rindge . . . J9 151 In Memoriam 153 Registration List 165 Exhibitors 167 Officers & Directors 169 Sustaining Members 171
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EROSION CONTROL AT WPPSS NUCLEAR PROJECT NOS. 3 AND 5 , G.S.Jeane II, L.L. King, andK.R. IVise Total Suspended Solids criteria, and stated INTRODUCTION ~t hat all nrface ruhoff facilities be designed to contain a 5.5-inch 24-hour rainfall. The Washington Public Poder Supply System (referred to as WPPSS and the Supply System) is a municipal corporation and joint Site Conditions operating agency as provided for by State of Washington law. The Supply System is The site of WNP 3 and -5 is situated on , made up of 22 members, including 19 public a ridge and adjacent bench sloping act-h-utility di-tricts and three cities. It constructs ward to the Chehalis River. Three creeks, generating resources to meet its enembers' Fuller, Purgatory and Stein bound the site needs and the needs of other Northwest a- on the west, east and south respectively. . gencies who wish to participare in its pro- The site development plan required substan-jects. The Supply System is presently con- tial excavation in order to provide adequate structing five nuclear power plants in Wash- foundation conditions in the underlying un-ington. Although three are in the eastern weathered sandstone. part of the state, the subject projects, WNP 3 and -5, are in western Washington, The site receives an average annual located about one mile south of the Chehalis rainfallof 65 inches (Iow 41, high 80). Labo. River near its confluence with the Sacsop ratory, settling tests identified that compli. River (Figures 1 and 2) ance with ti e 50 mg/l Total Suspended Sol. ids limit could not be achieved by using only During 1975, the State of Washicgton gravity settling methods (Figure 3) due to Energy Facility Site Evaluation Council the colloidal suspension that results when (EFSEC)1 held hearings on the National Pol- the clay and weathered products of the System lutant Discharge Elimm= tion sandstone are mixed with water. (NPDES) Permit and Site Certification for WNP 3 and 5. Federal Effluent Guidelines at the time suggested that the appropriate Design Emsion Contro/ Plan l i Total Suspended Solids (TSS) Effluent Limi-I - tation 'or construction runoff from power The principle features of the crosion control plant construction was 50 mg/l. They fur. system and plan for the Satsop site include tbr suggested that the erosion control sys ' certain features (Figure 4). A perimeter tem should be designed to handle and treat a ditch system drains all surface runoff from 10-year, 24-hour storm (5.5 inches for the the site to a large equencion pond at the Satsop site). On July 26, 1976, EFSEC is- north edge of the site. Following primary sued a NPDES Permit requiring all surface settling, flow compensated equipment in-runoff from the site " coper meet the Envi- jects a polyelectrolyte to promote coagula. ronmentalProtection Agency (EPA) 50 mg/l I Forme ly ThermdPoser Plasr Sac basanos Comscd ITPPSEQ
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r .- - pu.nping system, enlargement of the gravity tion of the suspended solids in the secondary collection ditch system and construction of settling pond. Cut and fill slopes within and aLweather rock roads to all pump stations. outside the contrc4 treatment system utilize seeding r.nd mulching on all slopes and jute- Evolction of the system was hampered lined ditches at 25. foot vertical increments. by limited access due to steep grades and Runoff from slopes at the site's perimeters is the lack of all. weather roads. Unless special pumped to the ditch system for treatment, precautions were taken, saturated fills mired heavy equipment. The inability to mobilize large amounts of equipment slowed system Record Rains and Resulting Erosion development. .The system consumed large Problems amounts of materials: 100,000 sandbags, The fira construction activity (April 55.000 square yards of " Hold Gro" fabric, 1977) was to clear andi , rub the site, and si- hay for mulching 3,000,000 square yards, multaneously construct tmtral rudimentary shecrete for 1500 linear feet of ditches, ditches and temporary set Img ponds at its mi'es of jute mesh for ditches and typar fab-north end (Figure 4). ". here gravity flow ric for roads, and 25 acres of reinforced plas-ditches were no feas,ble due to topography i tic ground cover. characteristics, multiple haybale check dams were cotablished. Subsequently, fili needed - to be placed curside of these ditches, and as EROSION CONTROLMETrf0DS this fi'l developed the ditches needed to be-moved out to the site perimeter. This pro- The majority of the methods utilized to cess was underway cur,mg the last ten days control cresion are listed and briefly evalu-of August when the site received a record atedin this section. rate:all8,5.0inchesinsevendays). A rainfall record was also set in December, while Sep. (f,,;;,jf, g,,;,,,g3,,,7;,gpg,g, tember and November had ram significantly above thei mean precipitation values. Ex- .Ihe colloidal nature of the site soil re-tensive floodmg occurred m the Chehalis R2- quired the addition of a polymer in order for ver Vr.Ilcy dur,ng i the winter of 1977. The the clarified effluent to meet 50 mg/l Total unseasonal rains not only caused s,ignificant Suspended Solids (TSS). A 15-acre by erosion, but consumed valuable construction 10. foot deep primary settling pond (Figure days, which made the completion of erosion 5) removed all rapidly settleable solids. A control features much more diffict.lt. chemical (Magnifloc 573C) was added to the effluent of these ponds prior to discharge Following the August 1977 rainfall, a into a 4-acre longitudinally divided second-number of add,nonal i erosion control meas- ary settling pond. The secondary settling ures were taken to combat er sion and tur- pond had a retention time of 28.5 hours at bid runoff. 'Bese included: temporary the design 10,000 gallons per minute (gpm) ditching; placing haybdes in ditches, stonn flow rate. This system consistently dis-drams and creeks; very mited pumping t charged effluent below 50 mg/ITSS. ' dtvett runoff to small holdmg ponds and straw mulchingof exposed areas. If confronted with the necessity to treat surface runoff, a series of settling cohuan These measures reduced, but did not tests should be conducted to determine if a control the erogion and mrbid runoff, and an chemical is needed and to select the most extensive erosion control system started t appropriate polyme r. Adequate safe-evolve. 'nus system mcluded heavy mulch. Suards must be incorporated to protect mg m all exposed are.ts, creanon of 2 major aquatic life due to the toxic nature of most 22
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l et polyelectrolytes. This method is successful and offer the greatest potential for massive 'j at meeting low Suspended Solids discharge failure (if constructed under emergency condi. , limits. tions), but when they are connected to an ade- ]ir l quate treatment system they produce a high s
. Major Coliccrion Ditche3 quality effluent. Whether there is a need to i remove the dikes at the end of construction y The site proper (280 acres) is bounded should be considered in choosing their loca-on the east and the west by 13,500 linear feet tion. k
, of gravity flow collection ditches that measure Z l approximately 2.5 feet deep and 10 feet wide. I ' Because of the large flow these ditches are re- FaterManagement On Unstab/< Slopes [ quired to convey, they are substantially built r and potentially weak sections are reinforced To prevent erosion, it is necessary to [ l with shotcrete, p'astic liners and sandbags. manage flow across unstable materials. On E ' cuts and fills, horizontal ditches are utilized on l Shotcrete all slopes, about half of which are outside the i[ ! central ditch system. The ditches are on 25- E l This substance is a thick nuxture of con- foot elevation centers and lined with jute " crete without the gravel aggregate. The slurry mesh. During construction at the upper ' is pumped to the application site and sprayed boundary for cut slopes, a ditch was estab- ' h on w.re mesh that is layed on the walls. This lished to collect surface water from above th'e E ! l material was utilized to protect the secondary construction area and route it away from the l l settling pond banks and longitudin=1 divider new slope. These ditches were extremely im. from wave erosion. Approximately 1,500 lin- portant in the process of removing and keep- {! g car feet of main ditches have been shotcreted ing water off unstabilized slopes. Steeply ; . to strengthen the banks and prevent saturation sloping ditches required the use of plastic lin- [ ;' of the outside bank and its supporting fill. Ing to prevent their erosion. Because of the Shotcrete is excellent material for long. term amount of water carried by the ditches, it was ;1 erosion control, but it must be applied in dry necessary, on large slopes, to use vertical l weather. down drains of either half.round corrugated metal pipe (CMP) or flexible or collapsible Pump Stations plastic down drains. Although the p:astic q l drains are lighter and eusier to anchor and in. i i Pump stations were installed to direct stall, they are susceptible to tears and dam- 5 turbid mnoff from outside the gravity collec- age. This type of water management system, tion system to the chemical treatment system. which utilizes properly maintained horizontal 4ly The quantity of water and sediment involved ditches and vertical down drains, can signifi- ; ; required the development of a system of ten cantly reduce erosion at the source. [ j pump stations, with 39 pumps, capable of i pumping 40,000 gpm (Figure 6). To prevent ! . silting and loss of storage capacity in the pump Grave / Blankets
. stations, it was necessary to install settling ]H ponds immediately upstream of the pump sta- In several instances, perforated CMP was I; tions. To guard against the loss of the settling placed in fills along with gravel and typar fab- f and pump pond dikes, it was necessary to rock ric2. to drain groundwater. Flexible down ll the dikes and shotcrete spillways. Cleaning drains or gravel faces on the fills were utilized 0 sediment out of the ponds was a mammoth to control erosion. In the project major fills, a y task for which backhoes, cranes and special series of perk pipes bedded in gravel and P high solidt pumps were utilized, s sealed with typar fabric transported ground.
The pump ponds are expensive to operate water out onto the fill face. To protect the e 2 f} A Depontprodmes made ofspun polypropylene meshfabric that allows
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( 1 the remainder of the season, wood fiber hydro-face, the distance betw n the 25. foot vertical , as gravel surfaced mulch with a mixture of seed and fertilizer was elevation ditch to th. sprayed onto the slope enabling germination I to allow the water to fiev out and down to the of grass, the ultimate soil stabilizer. Although next lower ditch in a. manner that would not the best times for seeding in western Wash. p ick up sediments, ington were during the periods of March 15 to
, June 15, and August 15 to October 15, some germination would take place most of the year, Ve/ocity Checks therefore all final slopes. were seeded and mulched shortly after completion.
Checks are utilized to slow the flow of water and retain the sediment that drops out ' of suspension. Staked haybales, dumped stone or sandbags were all used. The haybales Surface Protection Fabrics alone tended to be undercut, thereby allowing Another important technique. utilized in the sediment to pass. The most acceptable erosion control, was the placement of plastic method udr. red on our prdect combined sand. over the surface of very steep or very unstable bags overlapped with typar with staked hay. erodable slopes. On slopes where the use of bales on top. The fabric contains sediment ditches for water management is impractical, and pr ents undercutting of the haybales. due to steepness or unstable conditions, blan-keting the slope with plastic allows the water to be transmitted to the foot of the slope. The Riprap Ston, erosion control system of WNP 3 and 5 used several types of plastic. The most versatile Small riprap, measuring 4 6 inches, was plastic sheeting was one that was reinforced utilizedin some steep roadside ditches and for with synthetic mesh, which resists rips or repair of seeded slopes that had slumped. tears. At one time, approximately 25 acres of
- These slumped .reas were packed with small Pl astic were placed to protect slopes. A com-riprap to prevent movement of the unstable Plicated web of rope and partially filled sand-soilbeneath and to a!!ow passage of springs bags was required to hold the plastic down in or k.rge ground seepages without further ero. the wind. Hold Gro fabric 3was placed on high.
sion. Use of rock in steep roadside ditches ly erodable slopes in an effort to reduce ero-prevented damage to the ditch, but did not sion and promote revegetation. This material contain sediment, has only recently been used by the Supply Sys-tem, and its effectiveness is still under evalua. tion. . SeedandMulching Straw, hay and wood fiber mulches were used on the site. Both straw and hay mulches Taciafers were utilized on temporary slopes. The.most These chemicals are primarily glues appropriate kind was recently cut local hay, that can either be sprayed in applications' preferabi; containing a large amount of weed light enough to allow vegetation to pene-seeds. This hay,when mulched at a density to trate, or heavy enough to actually provide a provide complete ground coverage, provided a solid, nonporous surface. A limited experi-significant seed base of rigorous, indigenous ment was conducted which indicated no sig. plants that provide excellent soil stabilization. were Where wood fiber was used, it was difficult to cificant difference from areas that assure that the application rate was up to the heavily mulched with straw. desired level of 1500 pounds per acre-of fiber. On final slopes, or slopes not to be worked for 3
- Smps ofkraft paper um en un apolyper>pylene mesh.
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mar mM w. .- pn F , p L. Sea 7 ment Traps mulch was placed on somewhat compacted slopes, which were not too steep, it seemed to e Use of sediment traps was limited. A sed- serve the purpose of breaking up the rainfall d iment trap was placed in lower Fuller Creek to energy and reducing erosion. On steep slopes , collect cot se sediment moving down the this activity was not a useful control measure. [ stream. At the foot of a large unstable slope The pumping of waters from adjacent drain-aloag the access road, a trap was constructed ages to the control system was the only action F)~ to collect sediment washed from the slope. that could reasonably meet the site's stringent The trap was simple and functional. This effluent limitations. This was an expensive ? method proved very efficient; at the end of solution in that it involved considerable energy 3 i construction the trap can be left to fill natural- consumption, high operating costs, and re- g quired construction of expensive all. weather ly. access roads. The use of plastic protection on (j j F
- critical slopes was a successful control mea-
. SiltFences sure, but must be recognized as a temporary [
one, and that ultimate control requires a re- i These fences consisted of stakes or metal vegetation effort. All of these control mea. I l sures accomplished the goal of isolating the R fence posts laced with chicken wire. and covered with Typar. These fences were uti- site form the adjacent receiving waters and (!:
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lized in some site streams and gullies where allowing construction to. proceed, limited only l
, the ground was extremely soft and unconsoli- by the production ratet -hat could be achieved [
! dated. In all instances, the fences functioned due to moist soil condhns. The cost of the extremely well. erosion control system w. high, and the fact j that work was done on an emergency basis cer- [i
{ tainly was a factor. The experience here [ Sandbags should aid others in developing an adequate and timely program that could be more cost I l I The classical tool for emergency dike effective. building is the sandbag. In excess of 100,000 sandbags were used during the erosion control RECOAfMENDA770NS campaign. Sandbags were used between August 1977 and March 1978 both to check ve- Out of the experience gained at this site, a 1 V locity in ditches and to strengthen and in- number of recommendations applicable to a f-crease the height of dikes and ditches. Be- ,wide variety of construction projects can be l cause of extremely poor access to Stein Creek suggested. It is appropriate to look closely and F j basin (mudslides had inundated the existing critically at work staging so that a site is al-ways in a safe geometry where a contingency fl pond and dike), sandbags were used to con-i struct a new dike over the old one and a pump plan can bring about corrective action. That platform. A highline logging tower was erect- is, a plan should be developed before construc. L ed on the ridge and a cable suspended to tion goes forward and should be achienble
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below the dike construction area. Sandbags under adverse working conditions. An arsenal of erosion control methods and materials
,j were filled on top of the ridge from cement 5 trucks that carried only sand and were then should be available so that, in an emergency, transported down the cable to the work area. implementation of the plan is rapid and has no l contractual or financial restraints. The plan should be flexible in its ability to meet chang- g e
SUMAfARY ing conditions because even a small uncontrol- ( led area can generate an obvious source of ; The corrective measures discussed above'were turbidity. 2 successful to varying degrees. When straw [w i V 25 , 4 1 t
TI e most important factor is one concern. The EEluent Limitations applied to this ing attitude. As one undertakes a major project assisted in having a lower charn desir-earthwork project in a heavy rainfall area, ed degrec of turbidity control when the unusu-management must recognize that money, en- al August rains occurred. If a system that re-ergy and resources will need to be directed at lied on gravity settling and numerous ponds erosion control, and that this must be done in around the perimeter of the site had been the the initirl budgeting and staffing for a project. applied technology, it would have been possi-This approach is important from a public rela- ble to have maintained a higher degree of con-tiom viewpoint, as well. trol at interim construction stages. The Supply System is in the process of bringing these con. It is prudent management to know the cerns to the attention of the EPA to recom-quality, character and value of the biological mend alternative limits for adoption in future community in adjacent streams. This know. Effluent Guidelines. The Supply System be-ledge should allow regulatory agencies to ap. lieves the Effluent Guidelines should give the ply a reasonable level of control and will serve issuing agency some latitude to consider site-to lessen conflicts if unsubstantiated claim = specific conditions. concerning " biological catastrophies" arise. M w F l e 0 t 26 t
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v , HYDRAULIC MODELING OF THERMAL DISCHARCES INTO SHALLOW TIDAL AFFECTED STREAMS Howard D. Copp N. S. Shashidhara Professor of Civil Engineering Hydraulic Engineer Albrook Hydraulics Laboratory Ebasco Services, Inc. Washington State University New York, New York, U.S.A. Pullman, Washington, U.S.A. K. R. Wise
' Supervisor of ErSironmental Engineering Washington Public Power Supply System Richland, Washington, U.S.A.
f ABSTRACT A thermal-hydraulic model study was conducted to determine whether a sub-merged, multiport diffuser would induce buoyant plume dispersion that complied with water quality standards established for a tidal reach of river in western l Washington state. Certain tide / river flowrate combinations create conditions
' under which dispersion is least efficient and will require special operations of power plants that create the buoyant plumes. This paper descri'ves model tests of the tidal conditions and plant design specifically for waste heat disposal.
- 1. IhTRODUCTION The Washington Public Power Supply System is constructing two nuclear
; fired power plants near Aberdeen, Washington, approximately 20 miles above Grays Harbor. Fig. 1. A natural draft cooling tower will be an integral part of each plant to provide condenser water cooling. Makeup water will be supplied
' to the towers from a Ranney pumping system; blowdown from the towers will pass through supplemental cooling facilities for temperature reduction before dis-charging into the Chehalis River. A multipurt diffuser will deliver the blow-down water to the river.
Figure 2 illustrates the diffuser design and placement in the river. Blowdown from each power unit's tower will be, nominally, 2,700 gallons per minute or 6.0 cubic feet per second. The diffuser is designed for two unit operation. The diffuser site is subject to mean monthly flowrates varying from 780 cfs in August to over 16,000 cfs in January. River depths vary with posi-tion in the stream up to 9.5 ft at about 6,000 cfs, the average annual flowrate. Fig. 2. Velocities at this flowrate average about 2.5 feet per second. The hydraulic characteristics at the diffuser site are subject to tidal influences only at relatively low river flowrates. The Washington State Department of Ecology has classified the Chehalis River as having excellent water quality. Accordingly, the Washington Water Quality Standards stipulate the following with regsid to temperature:
". . water temperatures shall not exceed 18' Celsius...due to human activity. Temperature increases shall not, at any time, exceed t = 2S/(T + U ....
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*", an Scele 46DIF[UERPlPC$ 2* demeter SOUTH SANK RevtR Flow ,
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o and River Characteristics o 2 at the Diffuser STRLAW MYCRAULICS i l P l
hhen natural sonditions exceed 1d* Culstus. .no temperature increase the receiving w.ater temperature will be allowed which will raise by greater than 0.3' Celsius. For' the purposes hereof. "t" represents the pvrmissive temperature change across the dilution tone; and T represents the highest existing temperature in this water classification outside of any dilution :one" (Wash. State Dept. of Ecology,1977). Applying these criteria to monthly stream temperatures shown in Co'uan (2) of Table 1 results in the permissible temperatures outsiae a dilution tone shown in Column (3). In order to comply with the temperature requirements, the dif-forence between diffuser flow temperature and ambient river temperature must be less than those t values or .a are dilution tone must exist. Anticipated tes-peratures of the diffuser flow shown in Column (4): except curing May, temperature differentials always exceed the state standards so a dilution zone was proposed. Numerical models are available . to study atxtng phenomena in instances similar to this Chehalis River setting and one was used to study this. case. The stream velocities, particularly during tiJes, and the free surface charac-teristics are not property treated by the model at more than a short distance downstream from the diffuser ports. The Washington State Energy Facility Site Evaluation Council, which authorites operation of these two and other power projects, required definitive assessment of thermal loadings. Therefore, a physical model study was undertaken to examine the diffuser performance under a variety of anticipated power plant and river conditions. harm water plume dispersion was examined in the near vicinity of tne diffuser as well as farther removed therefrom to assess diffuser performance in relation to Washington State Water Quality Standards. fatte 1. sater Quattty standards for fesperature r*/ per ssitte reep. otteuser Assade Ottutsee anne - Rise 1*Cl flou se, eta (asstent toep.. t ) *s reep, r (*t) '*M t*c) 3 (1) (1) (3) (4) Jan e.J 4.e 10.3 1.1 3. 3 s.f Feb 3.s 2. 6 8.6 Star Apr s.O 2.3 As 10.0 1.6 10.s har June 11.4 4.5 13.1 July 14.4 1.3 16.1 aug is.6 4.2 47.s sept 11.7 1.s ts.3
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' values are taese unsca have been escoeded 7s4 of tae esse aver a 12. seat durattaa setort.
- 2. THE HYDRAULIC 50 DEL 2.1 Similitude The hydraulic model used in the study is shown in Fig. 3; it represented a 1,280-ft reach of the river at a scale of 1:12. A detailed discussion of similitude requirements is beyond the scope of this paper.* However, thermal-hydraulic models will simulate prototype mixing phenomena whenever gravita-tional, viscous, and inertial forces in the model are proportional, one to another, to reflect properly that proportioning in the prototype. This will not necessarily insure that heat transfer processes all will be simulated pre-cisely; transfer through the river surface to the atmosphere, for example, requires atmospheric conditions to be simulated. However, this and certain other procesres contribute only in a relatively minor amount to plume charac-teristics likely to affect stream ecology that were of interest in this study.
..a a tron Cw.at ur e esm sue.tv. .Case 2 event. Real time data are those determined from the numerical model.
l Model time is real time divided by Q (Lr = model scale = 12) which corre-l sponds to the ordinary Froude Law of Similitude. Model flowrates include ( quantities entering (or leaving) temporary storage as a result of water level l variation. Thus, during flood tide, model flowrates exceed those'of real time t and during ebb they are less. l I 1 i
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o E]g o f f f 8 f 10 t 12 t 14 f . 16 5 I O 2 4 6 , Time. hrs - Fig. 6. Tide Characteristics at Diffuser Site rate: riae sata for 3, e s?s .:fs and a 4.4 fr-est tue at werdeen a see Fig. ei seter Met' Mt' water Floerfste3 Real Surface River 4verste Model Surface f rom FMe TLas 41ev. Flowrate Telecity fine Eley. Upstream Downstream (br. eta) (ft. eel) (cfs) (fys) (esa) ( ft.es t) (cfs) (cfs) fit ( 2) e3t f at ett eat fM '97 0 3.49 571 0.43 0 1.49 571 3 3 3.50 50 0 10 3.82 534 0 13 3.84 10* 0 1 00 3.43 339 0.24 20 3.50 512 0
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%gative values tadicate upstreas direction.
**'alues snown are actual river quantities; meal quaatities are 1/499 times values snown.
'Fla= rates suo911ed to the model.
L
_m . . ._ . . 1 3.2 Test Procedure and Results Tides were created by varying model flowrate and water surface elevation as shown in Table 2 for Case 2. Diffuser flowrate and temperature were set at =
- predetermined values after which the diffuser flowwas diverted into the stream. -
After s'oeut 25 minutes the plume had reached equilibrium; the tido cycle then began. When flood tide commenced (at rest time of about 15 minutes for Case 2), flowrate from the upstream end of the model began decreasing. The upstream
- control gate on the model (see F12 3) was raised to prohibit out flow from that end of the modet; all outflow passed over the downstream gate which was slowly raised to increase river surface levels as time advanced.
- Shortly after upstream-directed river velocities began to occur, flow from
' the upstream end of the model ceased and that from downstream began increasing.
At this time (25 minutes model time for Case 2), the downstream gate prohibited
; outflow and the upstress gate was slowly adjusted to create appropriate river i
surface levels. Eventually downstream velocities began to occur again (during
' obb tide);accordingly, flow was again introduced from upstream and river levels were maintained by controlling the downstream gate.
4 Model tests reproduced an abbreviation of complete tides as illustrated a in Fig. 6. Approximately 6 of the 14 hours in each case were occupied by essentially steady state flow which did not influence the unsteady state plume dispersion. This is demonstrated later. Figure 7 illustrates dilution contours at various times during the 5.6 ft-asi tide and river flowrate of 440 cfs. Flood tido velocitiesAt here I hourreached and 10 nearly 0.5 fps--the highest of the three cases tested. minutes after onset of the tide, the dilution contours at the diffuser level (EL A) displayed a shape somewhat foreshortened and wider than those in Fig. 5 because upstream-directed river velocities had begun. During the next 15 to 20 minutes, stream velocities forced the plume laterally and upstream; low dilutions were centered around the right end of the diffuser. At 2 hours and 13 minutes, upstream-directed velocities were at their peak magnitude; this is. evidenced by the plume extent near the water surface (E1, C). At lower levels, the plume was more confined, however, indicating relatively strong buoyancy, Peak stage was reached - at 2 hours and 53 minutes but streaa velocities had reversed a second time, i.e., toward downstream again. The plume also reversed its direction a second time. By 3.5 hours, the plume appearance returned to the shape much the same as shown in Fig. 5. Figure 7 also shows the model tide that was created during the tests. It - conforms well with the computed prototype tide. Measured model velocities were at insufficient locations to compute mean values but available data suggests the model velocities conformed exceedingly well with prototype counterparts. 1he abbreviated model tide was indeed appropriate since the plume returned l to essentially steady state patterns after 3.5 hours. The concern of plume i
" fold back" proved to be - correct but this did not result in extensive heat build-up. Some localized warm spots existed near the diffuser but these were short lived.
The second tidal situation, ia., 570 cfs stream flowrate and 4.S ft-asl tide height, produced rather small upstream velocities. Peak magnitudes are less than 0.20 fps; velocities are within the +0.1 to -0.1 fp? range for less than one-half hour during the first flow reversal and for about an equal dura-tion during a second reversal. The first reversal occurs at about 1.5 hours time (see Fig. 6). Model tests of these conditions showed that the plume was i n
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n affected only slightly during the first 90 minutes. Thereafter, however, the plume began to spread rather widely, Fig. 8. At 2 hours, the plume spread from shore to shore in surface layers. Relatively wam :ones were concentrated near the diffuser. During the next 30 minutes, these :ones grew warmer and the plume in surface layers reached its maximum upstream travel. Thereafter, the plume returned to its downstream orientation--reaching steady state conditions after about 3 hours. The plume spread rather broadly in this case because the velocities were small for some time. Its areal extent and location were much the same as those observed during tests with ua = 0. Locali:ed warm spots occurred here as in the first case and were quite confined near the diffuser. A tide of 5.6 ft at Aberdeen and 700 cfs river flowrate creates peak stage height higher than either of the other cases but velocities during flood tide, in the upstream direction, are no greater than .at the lower flows and the duration when velocities are less than 0.1 fps (in either direction) is least of the three cases. These conditions began to affect plume dispersion in the surface layers after about 45 minutes. Figure 9 shows the plume thereafter. Near peak tide height, the plume had sp, read rather widely near the surface--more so than in Case 2. De warmer one was confined near the diffuser. After about 2 hours and 45 minutes, the plume was confined to definite downstream, middle-of-the-river orientation. The obje tive of the model tests was to determine if the diffuser per-formance would satisfy the water quality standards for temperature. Table 1 shows that TJ - Ta is greater than the pomissible temperature rise, t, in all months except May. Consequently, a dilution :one was proposed in which t could exceed those values in Table 1. He dilution :ene was 50 ft wide by 150 ft long with 100 of the 150 ft downstream from the diffuser. This zone is shown as a dotted rectangle in Figs. 5. 7, 8, and 9. Table 3 repeats Table 1 but Column (5) has been added which shows minimum required dilution factors for each month where Tj - T2
- TJ - Ta III D.F. min (T i - T )a max t
- Assuming a dilution :one .s adopted, dilution factors outside the :ene must be greater than D.F. min to comply with the water quality standards. October pre-sents the critical condition; if dilution factors of 5.4 or greater occur out-side the dilution tone, cogliance will be achieved.
All of the anticipated steady state flow conditions will comply with the standards with the dilution :one adopted. However, tidal conditions forced the plume out of the dilution :ones during short time intervals when dilution factors were less than 5.4 These occurred at I hour and 27 minutes in Case 1 (Fig. 7) and at 2 hours and 46 minutes in Case 2 (Fig. 8). In Case 3 (Fig. 9), a 5.0 dilution factor contour approached the edge of the dilution :one. In each instance, these conditions arose just as flow reversals (either the first or second one) occurred. n
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faale 3. Ottation Crtteria (16 (2) (31 (4) (3) Penissible Temp. ILise Required Mintas" ustent temp.. 2S Dilation Factor enth Ts T g,3,q) 3 ca co cc) m Jan 0.0 4.0 10.3 2.6 Feb 1.1 3.3 9.7 .3 Mar 3.9 2.6 5.6 1.8 Apr 5.0 2.3 8.9 1.7 May 10.0 1.6 10.8 0.3 June it.1 L.S 13.1 1.3 Jatr 14.4 1.3 16.1 1.3 Aug 15.6 1.2 17.5 1.6 Sept 11.7 1.5 18.3 s.4 5.0 2.3 17.5 5. 4 oct wv 4. 4 2.s 13.3 4. 4 Dec 0.6 3.7 12.8 3.3
- 4. MANAGEMENT TOOL APPLICATION Difficulty sometimes arises in making the transition from scientific study to decision making. In this case, the quasi-judicial administration board. the State Energy Facility Council, was presented with model result reports and expert witness testimony. Council members also visited the laboratory and observed demonstration tests. With the understanding of river behavior provided, the council established discharge permit conditions which considered both the river's fishery resource and the plant's operation.
These conditions required the discharge temperature to be such that tr e applicable water quality standards for temperature (those referred to earlier) , will be complied with at the edge of the dilution zone. Also, when ambient river temperatures are 20*C or less, the temperature of the effluent at the point of discharge is to be 20*C or less and may not exceed the ambient river temperature by more than 15*C. Whenever ambient river temperatures are greater than 20*C, the temperature of the effluent at the point of discharge is to be equal to, or less than, the ambient river temperature. The dilution tone was permitted with its volume being defined by: a) the water surface and the bottom of the river, b) 50 ft upstrema from the diffuser and 100 ft downstream therefrom, and c) 25 ft on both sides of the midpoint of the diffuser. Additionally, discharge flow must cease if the river velocity in the downstream direction drops below 0.1 fps. These creative conditions can be related quite closely tofisheries criteria. The Supply System has responded to the permit conditions with facility changes and acceptance of discharge operation procedures more complex than usual. The cooling tower basins are slightly deeper than normal to provide needed storage to accommodate the river velocity threshold condition. Because the water supply is by Ranney Co11ectors from an aquifer, the intake water is to be used to cool (counterflow heat exchanger) the discharge. v Y I e 5
?
4
- 5. CONCLUSIONS The hydraulic model proved to be a reliable tool to aid in assessments of diffuser perfomance and plume dispersion under i*eady state river flows and unsteady state tidal influences. ne model simulated the tidal phenomena extremely well and demonstrated the piume behavior equs11y well.
Critical dispersion conditions during the tide events occurred imediately after stream velocities reversed their direction as flood tide began as well as during the transition between flood and ebb tide. Velocity magnitudes at these time intervals were insufficient to generate turbulence for mixing or to carry the heat away from the diffuser. Physical modeling has played an importar.t. heat management role in that it not only developed knowledge of physical system bAavior but assisted in the presentation of that knowledge in a believable form to the decision maker. A working, believable model was instrumental in developing permit conditions which protect aquatic resources while providing considerable operational flex-ibility. ACKNOWLEDGMENT The authors wish to acknowledge the Washington Public Power Supply System for its assistance in executing the thermal-hydraulic model study which pro-vided the basis for this paper and for its permission to prepare the paper. REFERENCES
- 1. Ackers, P., "Modeling of Heated-Water Discharges," Chap. 6 in Engineering Aspects of Themal Pollution, Vanderbilt University Press,1969.
- 2. Copp, Howard D., " Thermal-Hydraulic Model Studies of Buoyant Effluent Dis.
charge Through a Submerged Multiport Diffuser," Tech. Rept. No. HY-2/79, Albrook Hydraulics Laboratory, Washington State University, Pullman, September, 1979.
- 3. Ebssco Services, Inc., " Hydrological Characteristics and Analytical Model.
ing of the Chehalis River in the Vicinity of Washington Public Power Supply System Nuclear Projects No. 3 and 5," NPDES Modification Request Summiary Report Appendix A, December, 1978. 4 Jirka, Gerhard and D.R.F. Harleman, "7he Mechanics of Submerged Altiport Diffusers for Buoyant Discharges in Shallow Water " Rept. 169, R.M. , Parsons Laboratory, Massachusetts Institute of Technology, Cambridge, March,1973.
- 3. Koh, Robert C.Y., N. H. Brooks, E. J. List, and E. J. Wolanski, " Hydraulic Modeling Outfall Diffusers for the San Onofre Nuclear Power Plant," Rept.
KH.R-30, W. M. Keck Laboratory, California Institute of Technology, Pasadena, January, 1974
- 6. Roberts, P.J.W., " Dispersion of Buoyant waste Water Discharges from Outfall Diffusers of Finite Length," Rept. KH-R-35 W. M. Keck Laboratory, California Institute of Technology, Pasadena, March, I???.
7 Washington State Department of Ecology, " Washington State Water Quality Standards," December 19, 1977.
l
..m 1
XIX CONGRESS Subject D(b ) New De lhi, India-1981 P ep e r Nts. 17 INTERNATIONAL ASSOCIATION FOR HYDRAULIC RESEARCH THERMAL-HYDRAULIC MODELING OF BUOYANT
. EFFLUENT DISPERSION IN SHALLOW STREAMS by Howard D. Copp, P.E.
Professor and Hydraulic Engineer Department of Civil and Environmental Engineering Washington State University Pu11maa, Washington 99163 USA and N.S. Shashidhara, Ph.D, P.E. Hydraulic Engineer Ebasco Services, Inc. New York, New York 10006 USA SYNOPSIS Dispersion of a buoyant effluent plume from a submerged multi-port diffuser in a shallow stream was examined on a 1:12 scale hydraulic model. The plume's extent was. defined in terms of two dimensionless parameters-a momentum flux
. ratio and a modified Froude Number--which incorporate flow rates .and tempera--
tures of the ambient stream and the diffuser. A series of empirical formula permit computation of the plume extent under specific stream conditions and dif-
# fuser operation.
RESUME l La dispersion de la plume effluente 15gere d'un multi-port diffuseur sub-tiergi itait examinie sur une e'chelle de modele hydraulique 1:12. L'$tendue de la plume (tait d$finie en termes de deux parametres sans dimension--la propor-tion du flux d'impulnion et du nombre modifie de Froude--qui incorporent le debit moyen et les temperatures du ruisseau ambiant et du diffuseur. Une sErie de formule empirique permit la supputation de l'[ntendue de la plume sous des conditions specifiques du ruisseau et de l' operation diffuseur.
- 320 -
IfrTRODUCTION A two-unit nuclear generating plant is being constructed in Washington State in Western United States by Washington Public Power Supply System, a l Washington Municipal Corporation. .Batural draft cooling towers will provide condenser water cooling. Makeup waters are necessary and blowdown from the towers will be discharged into the Chehalis River nearby after it has been previously cooled. A multiport diffuser will deliver the water to the river. The Chehalis River drains westward into the Pacific Ocean. Its depth varies from about 1.4 m during low flows in August and September to some 3 m at Noven-ber-March low flows. Corresponding velocities are 0.12 m/s and 0.76 m/s. Stream ,
~
vidth is about 76 m. The river is an attractive spawning stream for Pacific Salmon species and water quality standards must be maintained for this and asso-ciated water uses. This paper describes some of the studies to determine how ' vara waters would be dispersed in a rather shallow stream. DIFWSER DESIGN Figure 1 shows the diffuser plan adopted for study; this plan was selected based on Chehalis River hydrography, dilution characteristics required by water quality criteria, and techni- Table 1. cal errerience and research on various diffuser geome- b Ta af b/ T b/ Month tries. Stream hydrographic studies and examinations of g, ) (.C) (m ) ('h) cooling tower performance Jan 43.1 0.0 0.33 10.3 showed those values in Table 1 Mar 68.2 3.9 0.34 8.6 to be typical design para- May 37.0 10.0 0.36 10.8 meters. Diffuser flow rates Jul 15.3 14.4 0.37 16.1 are small compared to streen Sep 11.3 11.7 0.36 18.3 , flow rates and the differences Dec 19.1 0.6 0.34 12.8 in temperature are about 12*C '# - or less. - Stream flowrate and temperature. Diffuser flowrate and temperature. A surface, shoreline discharge structure was considered initially. This soon was discarded because the plume was apt to follow the shoreline which would create excessive ecological impact. The design of Figure I was adopted because , of its efficient mixing characteristics. A mathematical model was used to study sixing within some 0.45 a from the diffuser but effects of stream characteristics l (velocity and free surface, for example) are not properly treated by the model. g l i l
- 321 -
THERMAL HYDRAULIC MODEL STUDIES OF DIFFUSER PERFORMANCE The limitations of mathcaatical modeling of dilution characteristics pre-vented adequate assessment of impacts of warm water on Chehalis River water quality. A hydraulic model study was therefore conducted to study both near and far field phenomena. A 1:12 scale undistorted model, some 35 a long by 10 m vide simulating a 390 m reach of the Chehalis River,was built for experimental meas ~ urements at the Albrook Hydraulics Laboratory, Washington State University. The model included a replica of ths prototype diffuser; flow rates and temperatures
, therefrom could be set accurately at desired values over considerable ranges.
Copp I describes the model in detail. . The model scale was selected to insure that ambient river conditions and diffuser flow would be fully turbulent (as in the prototype); otherwise, dilution phenomena would not be sufficiently simulated. Koh et al. suggest that Reynolds3
, should be at least 1000; Jirka and Harleman Number for model diffuser flow, Rj, intermediate values. At a model scale (fr) suggest 3000 and others reconsend of 1:12 Rjm = 2.4 x 10 3so this scale was felt to be appropriate.
Some 250 thermistors, placed throughout the model and at multiple depthe, were used to measure temperatures of the stream both up- and downstream from the diffuser. A complete set of temperatures could be measured in about 2.5 seconds thereby allowing teaterature maps to be produced at any time during an experi-mental run. A run was terminated when the thermal plume reached pseudo-equil-ibrium. The model operation was based .on simulation of Froude parameters.,i.e., F u where: F is densimetric Froude Number; sub-Fr = 1= scripta p. m and r refer respective 1y to proto-8 / type, model and p/a ratio; g is gravitational
- 8 'E' acceleration and other terms are as defined in Figure 2. The stream and diffuser parameters in Table 1 are reasonable but actual flow rates and temperatures will vary with weather conditions and power generation rates. Thus, model experiments were designed from a parametric approach. Dimensional analysis can incorporate QR* OD, T, and Tj into two dimen-sionless factors-a momentum flux ratio, V = qjuj, and a modified Froude Number-q is discharge per unit of width of stream or of diffuser t
F= , length and Figure 2 defines other terms. The values in Table 1 produce V values i varying from 0.0884 to 2.403 with corresponding nF values of from 2.94 to 1167.60. Model experiments were designed to encompass these values. 1Copp, H.D., 1979. " Thermal-Hydraulic Model Studies of Buoyant Effluent Discharge Through a Submerged Multi-Fort Diffuser." Technical Report HT-2/79, R.L. Albrook Hydraulics Laboratory Washington State University, Pullman, Sept-ember. 2 Koh, Robert C.Y., N.H. Brooks, E.J. List, and E.J. Wolanski,1974. Nydrau-lic Modeling Outfall Diffusers for the San 07ofre Nuclear Power Plant," Report KH-R-30. W.M. Keck Laboratory, California Institute of Technology, Pasadena, January. 3Jirka, G., and D.R.F..Harleman, 1973. "The Mechanics of Submerged Multi-port Dif fusers for Buoyant Discharges in Shallow Water," Repore 169, R.M. Parsons Laboratory, Massachusetts Institute of Technology, Cambridge, March.
O '
- n. --
- 322 -
At each point of mixed temperature measurement, a dilution' factor was com-Tj-Ta puted as DF = At a point downstream from the diffuser, the lover.the Ti-Ta temperature Tg. the greater is the dilution from initial temperature difference Tj-T a and the larger is DF. Contour' maps of constant DF values were drawn as in Figure 3 which clearly show the plume behavior. For each experimental test, the area enclosed by the contours (A), a distance to that area's centroid'from the dif fuser (L )'e and a contour length (K )dwere determined and each.was plotted against 'F n and V. Figure 4 shows the influence of V and F non the area encompassed by two , contours, one at the diffuser level rud one near the stream surface. (There are - of course contours of higher dilutions so actual area of the plume is greater a than shown by Figure 4.) At 'the diffuser level, areal extent is almost independ- , ent of either V or Fn--this is typical of dilution factors up to about 20 ' although at CF > 16, area was slightly proportional, inversely, to 3Pn. ' At lesser depths, the inverse relationship 11 more apparent. Pere, as ambient stream velocity increases or as qj or AT decrease (other factors constant) dilu-tion occurs in less area or occurs more rapidly. The combined influence of V and Fa is illustrated on Figure 5 for the same dilution factors and levels as in Figure 4. Double regression analysis produced I representative equations for the data--a separate equation for each dilution factor at each of three levels. Two equations are shown in Figure 5 The same analyses were applied to relateet to V and Fn and xd to .V and Fn . Table 2 shows values for the resulting equations and provides sufficient information to predict the plume extent under specific operating conditions, Table.2. t I AREA c *d , ' Level DF k a b k a b k a b l 1 12.5 42 -0.52 0.008 23 -0.08 0.06 48 0.10 -0.15 - 16.7 705 -0.12 -0.36 36 -0.16 -0.02 78 -0.12 -0.17 20 1705 -0.41 -0.39 105 0.02 -0.15 147 -0.11 -0.13 2 10 19.7 -0.75 -0.24 0.3 -1.47 0.46 0.7 -1.4 0.37 12.5 25.1-1.13 12.5 6.4 -0.41 0.20 17.7 -0.22 0.17 16.7 98 -0.93 -0.02 17.1 -0.43 0.05 24.4 -0.67 0.004
*3 10 36 -0 .30 0.11 2.7 -0.61 0.14 6.2 -0.59 0.10 -
12.5 70 -0.36 0.08 6.7 -0.42 0.09 13.7 -0.41 0.08 16.7 322 -0.06 -0.06 22.9 -0.05 0.005 48 -0.02 -0.007 I I - p = kvar bn where p = area, t e or xd l I EXAMPLE: Let stream flowrate be 23.2 m3 /s with a mean depth of 1.5 m and an average velocity of 0.18 m/s. Stream temperature is 11.1*C. Diffuser flow is antici-pated at 0.37 m3/s and 13.1*C. ua9a v3 a The first steps will lead to computation of V = , and Fn* 2(op/p).gq) For convenience, let the total port area of the diffuser be 0.1 m so that uj = 10Q ; also assume the diffuser length is 10 m no gj = QD/10. q, in the product D of us and flow depth. Now, l l I t
. 323 -
0.183 = 69.8 y , 0.18 . 0.18 x 1.5
- 0.345 and Fn =
0.00023 x 9.81 x 0.037 J.1 x 0.037 Entering Table 2, the characteristics of the dilution contours can be determined. For example, at DF = 10 and Level 3,
-0.3 7 0.11 = 78.4 m2 A,= 36V
-0.61 F 0.1b = 92m' f 2.7V n xd = 6.2V
~'
'Fn *
- 17.5 m After similar computations for other contours, the plume can be illustrated as in Figure 6.
~ *,
The shapes of the contours are elongated ellipses which are cypical of those determined from model tests. At the diffuser level, shapes are different in the immediate diffuser vicinity where T, extends the full length of the dif-fuser. While DF = 10 was the lowest contout defined during model data analyses, lesser values of DF occurred closer to the diffuser. Actually, DF = 1 wculd exist at the diffuser ports. The effluent plume may well extend beyond the contours shown in Figure 6; contours of DF larger than 20 would completely define the plume. However, DF = 20 corresponds to Tj = 11.2*C in our example so the significant part of the plume is in fact shown in Figure 6. SLMfARY Mathematical modeling of buoyant effluent plumes often is constrained by boundary conditinns required to reach a solution to modeling equations. When I the receiving body of' water has significant ambient velocity and finite depth, a hydraulic model study is a practical means to define the plume extent. This paper has shown that a parametric analysis of experimental data is a practical way,to determine plume extent in wide, rather shallow streams. ACKNOWLEDGMENTS The authors acknowledge the Washingtor. Public Power :o .,0 f Jystem of Pichland, l Washington for its financial support of the hydraulic- Mel study and for its permission to publish this paper. l t l l l l l l l
- 324 - .
re<r . , ros.m re ar'use !s
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, svte so i 1
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Y _.V l As #s * #1 f , T* #e . l
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- I A = area enclosed i 0 t on & by contour ,
p
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+
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FIGURE 3
=
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- 325 -
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' o Thermis tors --o-
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. \4 _
A A \
,e t t t ti f f 'A' '
O.1 10 102 103 10" 10 _ , ,,,,n, . . ..en . A, m2 6 - A = 36V-0 301F011 FIGURE 4 g . N -
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o DF = 10 i 2 - o j -
. o a oa
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d
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2 - A =705 V-0.121F-0 38 ~ FIGURE 5 g,j , , e i n nl t i e i mit 10 102 103 Area Enclosed by Dilution Contour, m2
l
. j .
- 226 -
r LEVEL 1 ek'"c" 03 ) m H5b om LEVEL 2
- 40 0 20 ,
scale, m ~ d5 7 m' ' LEVEL 3 l I FIGURE 6 1 i 1 I b 1 D I
e : ( PREVIEW OF TOXICS CONTROL - A CASE STUDY ON COPPER Presented at Edison Electric Institute /Envirosphere Conference Environmental Licensing and Regulatory Requirements , Affecting the Electric Utility Industry October 21-24, 1979 i i Arthur Chu, Ph.D Manager Life Sciences , G Envir asphere Company A Division of Ebasco Services Inc 19 Rector Street' New York, N.Y. 10006 l t
TABLE OF CONIDTRS ( . I. INTRODUCTICN II. BACEGROUND A. SCIDTrIFIC AND TECHNICAL PAGGROUtc
- 1. Copper in Power Plants
- 2. Occurrence in the Environment
- 3. Behavior of Copper in the Aquatic Environment
- 4. Environmental Pathways of Copper
- 5. Biological Effects of Copper B. REGUIA'IORY BACEGROUPO l 1. Technology-Based Effluent Limitations
- 2. Water Quality-Based Standards
- 3. Proposed Water Quality Criteria on 65 Toxic Pollutants l
! III. CASE S'IUDIES CN CDPPER
, A. BACKGOUIC EVENIS B. CASE A C. GSE B D. CASE C IV. LESSONS LEARNED REFERENCES t.
l l 4 e I
. LIST OF EXHIBITS t,
EXHIBIT NO. TITLE 1 Copper in Power Plants 2 Occurrence of Copper in the Aquatic Environment 3 Chemistry of Copper in the Aquatic Envirorsnent 4 Acute and Chronic Values for Copper 5 Copper Effluent Limitations for Stearn Electric Generating Sources 6 Boiler Biradown, Raw Waste Concentration 7 Exanples of State Water Quality Standards for Copper 8 Criterion for Copper 9 Copper Criterion to Protect Freshwater Aquatic Life Hour Average 10 Copper Criterion to Protect Freshwater Aquatic Life - Maximum 11 Case Studies on Copper at Power Plants 12 Stenary of Positions on Copper Discharges 13 Copper Concentrations in the River t l l l i l l l t
I - INTRODUCTION During the past decade we have witnessed the emerging impor-tance of toxic or hazardous subatance control in the public and private arena. The driving forces behind'this trend are many, but to a large extent they !!$ ve been prompted- by combination of several factors: widespread public concern or awareness over environmental damages caused'by toxic materials; the consumer protection movement; lawsuits, and advances made in science and technology stressing the need for preventive measures to shield the public from harmful chemicals as opposed to costly cleanup activities following espisodic damages. The impact of these activities has culminated in several important pieces of legis-lations which have been enacted to collectively control toxic or hazardous substances in the environment. These are the Safe Drinking Water Act of 1974, the Toxic Substance Control Act (TOSCA), the Resource Conservation and Recovery Act (RCRA), both enacted in 1976, and the Clean Water Act (CWA) of 1977. Various aspects of these laws directly or indirectly affect the electric utility industry. Those related to CWA will be the focus of this paper. A key objective of the CWA is the control of toxic pollutants. In its effort to implement the toxic control program EPA has revised the National Pollution Discharge Elimination System (NPDES) permit regulations to allow reopening of permits to in-corporate new toxic pollutant effluent limitations pursuant to Section 307(a) of the act (44 CFR 34346) . EPA has also ini-tiated efforts that could result in more stringent water qual-ity standards that currently exist in many states. For exam-ple, it has recently issued proposed water quality criteria on the remaining 12 of the 65 pollutants listed as toxic under the CWA. These criteria could be incorporated in the states water
quality standards. With these activities as the scenario, the g purpose of this paper, then, is to provide a preview of toxic substance control, as it relates to the electric utility industry. Specifically, the topic will be addressed from the point of view of one of the 65 toxic pollutants, namely copper. Five basic areas will be covered in the paper: (1) an overview of the significance or importance of copper as a material to the electric utility industry, (2) a descriptive background on what we scientifically know about this element and its biological or toxicological effects. (3) A brief dis-cussion of how copper is presently being regulated today, (4) an analysis of several case studies on copper in relation to power plants to illustrate a trend in the control of toxic sub-stances in the future, and (5) the impact the proposed water quality criteria will have on the regulatory requirements of the electric utility industry. l l r
N s II - BACKGROUND f . A. SCIENTIFIC AND TECHNICAL BACKGROUND
- 1. Copper in Power Plants Copper is probably one of the few substances on the 65 toxic pollutant list that is likely to be found in liquid discharges from all stream generating electric f acilities (Exhibit 1) .
With rare exceptions, copper is the material of choice in a wide variety of components in power plants, inc b ding heat ex-i changers of various sizes and types, boiler plate material, piping and valves, pumps, etc and is also used as a chemical additive for specific purposes. The single largest use of copper in most power plants is probably in the circulating cooling water system principally in the form of condenser tub-ing and piping. In fossil-fueled plants it is also a major constituent of boiler metal and the high and low pressure feed-water heater tubes. Copper is the material of choice for several reasons: (1) it has excellent heat transfer properties; (2) it is malleable and therefore has excellent working properties; (3) it forms a wide variety of useful alloys; ( 4) copper-alloys are chemically re-
.. stance; (5) copper has relative economic advantages over other materials with'less heat transfer properties; and (6) it has inherent biocidal properties. For example, copper sulfate is frequently used to control algae formation in recirculating cooling water systems, particularly in cooling towers. Copper is also chemically added to cooling water systems as a constit-uent of proprietary scale or corrosion inhibitors.
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; 2. Occurrence in the Environment Copper is a ubiquitous but minor constituent of virtually all natural waters examined thus far. The concentration of copper found in a survey of 1600 surface waters of the United States ranged from 1 to 280 ug/l (NAS, 1977). Where high concentra-tions of copper are found in raw water, for example, in excess of 500 ug/l pollution from industrial sources can be suspected.
The mean concentration for most U.S. water is around 15 mg/l (Exhibit 2) . Mean values for different drainge basins in the United States ranges from 7 to 27 ug/1. Copper levels in the Pacifi'c Northwest where the waters are typically soft and low in alkalinity averages about 9 ug/l with a range of 1 to 37 ug/1. Copper in pristine water, such as mountain lakes, are ! generally near the lower end of the concentration range. Sources of copper in surface waters are too numerous to list. f They may be natural or antropogenic in origin. Copper is ubi- , quitous in rocks and minerals of the earth's crust occurring usually as a sulfide or oxide but occasionaly as free metallic copper. Typical crustal concentrations of copper are around 50 ppm, except in ore depsosits and marine sedimants where they may exceed 400 ppm. The weathering pregess and solubilization of copper-containing minerals account for the largest natural contribution of copper in most surface waters. Decomposition l l of vegetation and animal. matter also contribute small amounts of copper to the water environment. Man-made sources of copper include mining and industrial liquid effluents and fallout, agricultural and forestry sources, land clearing activities, 1 f copper in food, sewage treatment facilities, the use of copper as an algicide, and corrosion of copper piping in electric power plants and water distribution systems. The smelting and refining industries, metal fabricating and electro-plating in-dustries, copper milling plants, iron and steel industries, and l
! combustion of fossil fuel are the major industria1 sources of
.; copper in the environment. Precipitation and atmospheric fall-out of air pollutants or direct discharge of liquid effidsnts produced by these industries are mechanisms of whereby copper enters the aquatic environment.
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- 3. Behavior of Copper in the Aquatic Environment The behavior of copper in the aquatic environment is shown in Exhibit 3. Once copper enters surface or groundwaters its be-havior is governed by a number of chemical and physical fac-tors. In simple terms, copper can be characterized as either being in a dissolved (soluble) or particulate form. Copper ex-hibits different degrees of chemical reactivity. It can exist I. as the free cupric ion, it can form loosely bound or tightly bound complexes or it can precipitate with many inorganic and organic constituents normally found in natural waters. It also can be adsorbed by clay, sediment and suspended organic partic-ulates. Chemists describe these reactions as complexation, chelation, ion-exchange, and adsorption phenomena. Thus the amount of various copper compounds and complexes that exist in solution will largely be dictated by such variables as pH, alkalinity, temperature, hardness and the concentration of in-organic and organic complexing substances. As a result, only a small proportion of the total copper found in natural waters is l
present as the free cupric ion, probably less than 10 percent in most waters and less than 1 per cent in eutrophic waters. The same chemical mechanisms that control the form and distri-bution of copper in natural waters will control the behaviour of copper within the circulating cooling' water system of a power plant (Exhibit 3) . The source of copper is predominantly tube corrosion products from the condenser tubes. Typically, copper is found as a dissolved.or particulate copper. The i T- *e--9 y - --~----r9y-= '--w-----'+F'N
1 t former can be either ionic or complexed copper. In power plants employing cooling towers frequently more than 50 percent of the total c6pper exists as particulate copper. About 10 I percent or less of the soluble copper is ionic. The cooling ! tower sediment usually contains between 1000 to 6000 times the copper in the circulating water. Thus, it serves as a major sink for copper in closed cycle systems.
- 4. Environmental Pathways of Copper c The final environmental sinks in the natural biogeochemical cycle of copper are the sediments of lakes and the ocean. Be-tween the sources and sinks, biological materials influence the distribution and composition of copper in the environment.
Copper is a required micronutrient and, consequently, organisms have evolved mechanisms to accumulate copper against environ-I mental concentration gradients. These mechanisms include par-ticulate ingestion, direct assimilation of complexed or chelat-ed copper and ion transport at membrane surfaces. Benthic and [ detrital feeders will concentrate copper over 4000 times the leve3s in the surrounding medium while aquatic plants and fish concentrate copper to a leser extent. Copper is not magnified in the aquatic food chain in the same manner as pesticides or mercury and, presently, does not constitute a hazardous sub-stance in the aquatic environment. However, with the continued use of copper-containing material, it can be expected that the copper concentrations in surface and groundwaters, as well as the atmosphere, will increase.
- 5. Biological Effects of Copper Unlike most of the substances found in the list of 65 toxic pollutants, copper, along with zine and nickel are the only one that are essential nutrients for both plants and animals at low
4 concentrations. However, at high concentrations it can be ( acutely toxic to a wide range of organisms which is why copper compounds have been historically utilized as algicider to con-trol growth in water supplies, as fungicide and molluscicides. It is widely accepted that the ionic form is the principal l toxic form of copper. Complexed or chelated forms are rela-tively harmless compared to the cupric ion. Its mode of action can be quite diverse. It can act on enzymes and cause enzyme inhibition on the cellular level, it can produce lesions at the i tissue level, it can cause death of whole organisms, or it can reduce populations in the aquatic environment in areas of severe copper pollution, as in the case of mine tailing wastes. The toxicity data base for copper effects on both freshwater and marine biota is quite extensive although most investiga-tions have dealt primarily with the acute lethal effects of copper. Exhibit 4 presents an overall summary of the available data in a rather simplistic fashion. From the available exper-imental data collected in the laboratory the following effects, and the threshold concentrations of copper for these effects, have been observed: The 96 hour LC50 for salmonids is between ! 10 and 100 ug/l in softwater with low complexing capacity and as much as 10 times higher' in hardwater or waters with high complexing capacity. For other freshwater fish, the values l range from 50 to 500 ug/l in softwater, while in hardwater a range of 50 to 1,000 ug/l is reported. For exposure. levels l longer than 96 hours, values between 7 to 18 ug/l are reported for 200 hour LC10 in juvenile steelhead trout and chinook I salmon, the maximum acceptable concentration reflecting little l or no mortality in rainbow trout is betw'een 12 and 19 ug/1. l Concentrations that have "no effect" on salomid range from 3 to t l
o ( 20 ug/1. The response of other freshwater fish to chronic , exposures of copper are generally similar to the reported safe concentrations observed in salmonids. The 96 hour LC50 for I invertebrates ranges from 20 ug/l for a freshwater amphipod to 1,700 ug/l for snails. Insects generally exhibit a high tolerance for copper. Acute values for two species of marine fish range from 38 to 510 ug/1. Marine inverbrates appear to l be more sensitive than saltwater fishes (Exhibit 4) chronic values on marine organism are sparse; none have been reported ' for fish and only one has been reported for invertebrates where values ranging from 38-77 ug/l cycle were observed. Thus, aquatic organisms may be grouped into three classes of response to copper: sensitive, intermediate and resistant, although differences among phylogenetic groups and species within one group do exist. Among freshwater fishes, members of the salmonid group, such as salmon and trout are the most sensitive groups, while minnows are intermediate and cyprinids such as the bluegill are more resistant. Freshwater inverte- ' brate organisms also exhibit a wide range of sensitivity. The information on marint organisms is not nearly as extensive as 4 for freshwater forms. In general, marine invertebrates appear to be more sensitive than fishes. Finally, the available evidence indicates the particular life stage, method of copper application (ionic vs particulate) , and water quality variables l are important factors which determine the susceptability of aquatic organisms to' copper. B. REGULATORY BACKGROUND I l
- How is copper beinge regulated today? Essentially, copper is i
! being regulated by two different approaches or mechanisms. One is water quality-based through the adoption of water quality standards and the other is through technology-based effluent limitations. i
e . . - __ _ ( The regulation of copper in the electric utility industry for both the technology-based effluent limitations and the water quality-based standards are accomplished under the NPDES permit program. The permit program is administered by EPA until such time as the program is delegated to the States.- Presently over 30 states have been delegated NPDES permit granting authority.
- 1. Technology-Based Effluent Limitations The current technology-based effluent limitation for the steam electric utility industry are shown in Exhibit 5. It should be noted that EPA is planning to promulgate new effluent limitations next year. For the most part, effluent limitations on copper exists only for two effluent sources, metal cleaning wastes and boiler blowdown.
The water quality of boiler blowdown is generally high, and frequently higher than that of the intake water, so that it is suitable for internal reuse in the power plant. Therefore, most fossil-fueled power plants examined thus have little difficulty in complying with the 1.0 ug/l limitations (Exhibit
- 6) . Because copper is a prevalent constituent of boiler metals, boiler tubes, condenser tubes, hot wells, pumps, etc.,
it is not surprising to see a limitation on this waste stream. However, metal cleaning operations occur so intermittently that adequate precautions can be taken to control their discharge. On the other hand, no effluent limitations presently exist for once-through cooling or cooling tower blowdown, which are continuous discharges. i 2. Water Quality-Based Standards Even without technology-based etfluent limitation on continuous streams, copper can be been regulated through water quality-
( based requirements as in the case of adoption and enforcement by the individual states of water quality standards. Exhibit 7 presents some examples of the water quality standards for cop-per in a few representative states. In each case, the highest designated "use" category where possible was chosen. Generally, this was for the protection or propagation of fish and wildlife resources. It is quite evident from the exhibit that different states regulate copper differently and therefore le~ss con-sistent than the technology based limitations. Four different approachs have been en- countered (1) the use of a numerical concentration limit which supports a given use category (2) employing an application factor approach, that is, a percentage generally one or ten percent, of the 96 hour LC 50 vaice (this value is experimentally derived from bioassay studies) (3) A qual- itative criteria under the general heading of " toxic substances" such as " Toxic Substances shall,be limited to prevent. harmful to human fish, wildlife and aquatic life" etc and (4) no quantificative or qualitative stan- dards at all.
- 3. Prooosed Water Quality Criteria on 65 Toxic Pollutants Within the past year, EPA has -issued water quality criteria for the 65 toxic pollutants including copper. These criteria were developed pursuant to Section 304 of the CWA and in compliance l with a court order (NRDC/ EPA Consent Decree) and are now available for comment. The criteria are to state the maximum l recommended permissible concentrations (including appropriate zero) consistent with the protection of aquatic organisms, human health and recreational activities.
Exhibit 8 presents the criterion for copper as it appears in the Federal Register July 25, 1979 (44 FR 43666) and compares it wfth the same criterion in EPA's current (1976) water
o . I quality criteria, the " Red Book" criteria. Exhibit 9 and 10 are graphical representations on the proposed copper water quality criteria for freshwater aquatic life. The proposed criteria incorporates several new features not previously found in the " Red Book" criteria for copper. There now exists for each pollutant where adequate data exist, a two-fold criterion consisting of a 24-hour average value, based on chronic data, j and an instantaneous maximum value based on acute data. The use of the 24-hour average in chronic value departs from the
" Red Book" of setting a criterion irrespective of time.
Another feature is the use of a sliding scale to account for the variation of cepper toxicity depending on the degree of hardness. While final publication of these criteria have no regulatory impact on any party they could be used to develop enforceable l standards under several sections of the CWA which deal with water quality-based effluent limitations such as Section 302 t and water quality standards pursuant to Section 303. l With respect to water quality standards the key issue appears
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to be: "to what extant will EPA require its criteria to be incorporated in by the states in their final standard setting process". EPA has already raised this question in a Federal Register notice in an Advance Notice of Pro- posed RUlemaking (ANPRM) (43 Fed. Reg. 29588, July 10, 1978). As indicated in that notice, while it is EPA's current policy not to promulgate standards for pollutants which states have not addressed in their standards, it might alter this policy for the 65 toxic pollutants EPA has informally indicated that in future rule making effort it might " provide a list of pollutants for which water quality standards must be developed by the states of EPA". It is obvious that the water quality criteria that have-been issued thus far, which includes copper, will be the
( basis for determining future water quality standards. This in turn will govern industrial discharges, including those for the j electric utility industry,and thus will dictate'the ultimate i characteristics of our nation's waters. 1 l I q l l i l
E III - CASE STUDIES ON COPPER Exhibit (11) presents a summary of three case studies which deal with copper as a potential toxic pollutant in power plant effluents, primarily from the circulating cooling water j system. The cases will be presented in chronological in order to illustrate a trend or preview of toxic control, especially the 65 toxic pollutants. Each case involves some aspects of the regulatory process whether or not the regulatory proceeding addressed the copper issue specifically. Before discussing these case studies individually it might be instructive to examine briefly the background events that led to some of these case studies. A. BACKGROUND EVENTS It had become apparent to some investigators in the early '70's that the discharge of copper corrosion products from steam electric plant and facilities such as desalination plants could pose potential hazards to aquatic ecosystems, particularly in , the marine environment. The concern stemmed from the well known case of the effect of copper corrosion products on the oysters downstream of the Chalk Point Plant on the Patuxt'nt River, the so-called " green oyster effect" (Roosenbe rg , 196 9) . This plant, which employed a once-through cooling system, was initially installed with stainless steel tubes, which lasted 2 months. The tubes were subsequently replaced by aluminum bronze tubes, which lasted less than one year, and later replaced by copper-nickel tubes. Oyster meat near the 9 4
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discharge began to display green color shortly after_the plant initiated operation. The greening of the'Patuxent oysters was probably caused by the uptake of copper because there was a f strong correlation between the green color and copper content in the oyster meat. Furthermore, the copper content of oysters decreased with distance f rom the discharge. Several years later, Alexa'nder (1973) investigated the levels of copper released from an electric generating facility in New York which employed admiralty brass as the condenser tubing material. The facility was located in an area where important shellfish resources existed. Averaged copper releases from this once-through system which discharged into coastal waters were less than 10 ug/1. Furthermore, the older the generating units, the less the release rates were. Subsequently, a series of field studies was conducted by Compton and Corcoran (1974) at nine marine facilities in l Florida which contained copper alloy tubing. These authors concluded that the levels of copper observed in the discharge and in the vicinity of the plant were well within the range of the copper content of the surrounding waters. They observed that coppet could exist in several forms, ionic, particulated and complexed. Compton and Corcoran (1974) concluded that factors other than the copper content of the sea water discharge were found to have a greater impact on the marine ecosystem near the facilities. 5 B. CASE A The background information for Case A is as follows: The site is located on the west coast of the United Stater. The plant was under construction and employed a once-through cooling system which discharged directly into the Pacific Ocean. The condenser tubes were made of 90-10 copper-nickel alloy. The project was in the midst of its final licensing phase for an
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g NRC operating license pursuant to 10 CFR Part 50. S ta r t-q) operations of the seawater cooling system had been underway for i a month at the time an incident attributed to the effects of copper was reported. State fish and game biologists monitoring the construction of the unit observed stressed and dying shellfish in the vicinity of the discharge. This discovery set into motion a chain of events that culminated in the public disclosure the following year of the owner's decision to remove about 2.5 million feet of the copper-nickel tubing and to replace it with titanium. From investigations conducted by the state agency after the shellfish incident was reported, including those performed by the owner, a number of facts could be linked to trace the events that led to the decision to replace the tubing mater-ial. They included the following: i
- 1. By the ti me the affected shellfish pooulation was ob-served, the main circulating water pumps for the unit had been operating intermittently for a total of 220 hours. However, between pump runs they stood idle.
During these idle periods, the main condensers were filled with air instead of seawater because the condensers were located approximately 50 feet above sea level. The seawater simply drained into the ocean when the pumps were turned off.
- 2. Following the discovery of dead or dying shellfish, chemical and physical investigations were initiated to determine the nature of the toxicant, which was sus-pectea to be corrosion products from the condenser tubes. It was established that alternate exposure of the tubes to seawater and air resulted in the forma-2 tion of a loosely adhering insoluble film of copper corrosion product (chemically a copper complex). Dur-
ing subsequent startup operations relatively high concentrations of this copper ~ complex were discharged into receiving waters. But this phenomenon was temporary because background levels of copper were observed in the discharge within a few days.
- 3. A number of biological investigations were conducted, both by state agency personnel and by the owner. The initial findings of the state biologists indicated that a 96 hr LC50'value of between 50 to 70 ug/l cop- ,
per could be obtained utilizing copper sulfate solu-tion as the toxic form of copper. Subsequent tests by the same group utilizing the insoluble copper corro-sion complex from the plant indicated that acute lev-els between 150 to 200 ug/l could be obtained. The owner's biologist also examined the sublethal effects of the corrosion products and established that a level of 390 ug/l could cause shellfish " failure to respond . to tactile stimuli".
- 4. It is safe to conclude that a small number of shell-fish were killed by the copper corrosion products as a result of peculiar conditions occurring during the in-itial start-up operations of the circulating water pumps. Intermittent testing of the cooling water sys-tems later that year did not result in additional shellfish kills.
- 5. The " shellfish kill" received a great deal of notori-ety in the news media as a result of the investiga-tions conducted by the state agency.
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- 6. The engineering requirements imposed by.the designers of the power plant for a " leak-tight" condenser and l the owner's past experience with leakage in the cop-per-nickel alloy provided an opportunity to replace the alloy with titanium.
l While the owner 's announcement to switch from ' copper-nickel to 1 f titanium relied on its well-publicized problem of copper in the power plant effluent, there were indications in'some quarters that the decision to switch materials was not entirely neces-sary. Data collected by the owner on copper in the effluent during test runs subsequent to.the shellfish incident suggested that copper did not pose an ecological problem in the cooling ' water discharge, except very briefly at start-up and only under peculiar conditions. The apparent transient toxicity problem in the ef fluent could be averted by taking precautionary mea-sures during startup and was not sufficient reason for changing the condenser tubes. However, because of potential delay in obtaining the operating license the owner voluntarily announced the switch of material. s C. Case B The second case, Case B, involves a proposed project on the east coast of the United States. The site is located on an es-tuarine reach of the river. This section of the river is known for its valuable fisheries resources. Extensive f.ield studies indicate that the area is an important sspawning and nursery area for many species of aquatic organisms. The proposed fac-ility, which will generate about 2,400 Mwe electricity, will employ a closed-cycle cooling towers system, and 70-30 copper-nickel condenser tubing. 1 The proposed project was in the process of undergoing joint state and federal environmental hearings on the suitability of the site. Prior to the hearings, the state agency responsible for certification of the site undertook and independent envi-ronmental evaluation of the site. Among its findings was the rejection of the owner's proposed use of copper-nickel alloy condenser tubing. In addition, the federal agency with similar licensing responsibilities concurred with the state's analysis even though in its own analysis initially it did not consider the copper-nickel tubing or its corrosion products to be a problem. _~ ... - - - - _ . - .
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The reluctance both regulatory agencies exhibited on the use of ( copper-nickel' condenser material appeared to be based on the (1) demonstrated effects of copper on biota indigenous to the river, (2) the likelihood of copper being released into the river as a result of corrosion and erosion, and ( 3) the owner's suggestion that for economic reasons, titanium may be a better choice of material. They argued that laboratory data indicated that the juvenile stages of one of the most important fishes of the river was very sensitive to copper. The 96 hr LC50 for l this species was reported to be 50 ug/l and, furthermore, tox-icity was observed at levels as low as 10 ugII. Employing nearfield models of the proposed discharge, the state was able l to estimate the areas of the river covered by the toxic concen-tration levels. From this analysis different experts concluded that there was a real threat to the aquatic ecosystem. They admitted, however, that there were a number of uncertan-ties associated with this analysis of the problem namely: (1) their estimation of corrosion rates; ( 2) the chemical form of the emitted copper and its dispersal in the environment; and (3) the possibility of increased toxicity due to synergism or decreased toxicity due to antagonism. i l Nevertheless, in light of the available evidence, the experts for the regulatory agencies strongly recommended that the cop-per-nickel condenser tubing be replaced by titanium. The ap-plicant did not contest the issue even though the regulatory agencies indicated that they would not approve of copper-nickel tubing at the time. They did indicate that the selection and approvtl of the condenser material might best be deferred when ' ' results of future studies on the release rates of copper and toxicity of copper become available to render a more definitive answer. i l I y y ,- ,..,,,,.-,%, m. _ . , .m, m_, . . , , . , . . . . , . _ , . _ , , _ - _ - , . , , , .
D. CASE C ( Case C involves e site located in the Pacific Northwest of the United States. The project is located in a state that has NPDES permit granting authority. The project, a 2500 MWe gen-erating facility, is presently under construction. The fac-ility will discharge cooling tower blowdown and the other liquid effluents into a modest size river for the Pacific Northwest regio'n. The river discharges into the Pacific Ocean. The river contains.a valuable and productive fisheries resources, principally various salmon and trout species, which are adapted to the clean and cold waters that are typical of the Pacific Northwest. The fishery resource is a significant issue because it represents an important and economic recreational resource throughout the region. In 1974, the owner filed for a NPDES permit before state regu-l latory agency as part of the licensing process for the facil-ity. As a result of regulatory review process and public hear ings, the applicant was granted, in 1976, a NPDES permit which contained a number of conditions on the discharges from the fa-cility that were more restrictive than those proposed by the owner. One such restriction involved copper from the cooling tower blowdown. Another was no allowable mixing zone. The copper discharge concentration stated in the NPDES permit was 1.3 ug/l total copper. This concentration had to be met at the "end-of-the-pipe". The state does not have any numerical l limits on copper in its water quality standards. However, dis-charges of toxic substances, such as copper, must be limited to concentrations which would no cause acute or chronic effects on aquatic biota of the receiving water. The regulatory agency's primary concern with copper was the potential toxic effects of copper on the valuable salmonid and trout populations. The aim of the state regulator was to protect this important resource using water quality standards and, therefore, they calculated a
1. discharge value that would achieve this purpose. The recirculating cooling water system, as it was designed then, contained 90/10 copper-nickel tubing in the main condensors. However, because of the restriction in the permit, the owner decided to replace the copper-nickel tubing with stainless steel. While this decision would substantially reduce the risk of ad-ded copper on the aquatic biota of the river, trace amounts of copper would still be expected in the cooling tower effluent.' The reason for this was the use of a closed-cycle cooling sys-tem which was expected to concentrate, through evaporation from the cooling tower, copper in the makeup water supply plus the small amounts of copper corrosion products from miscellaneous copper-containing components of the recirculating cooling water system. Under the new design over 90% of the original amount I of copper containing material was removed or replaced. The ap-plicant, therefore, was still faced with meeting a discharge concentration of 1.3 ug/l which was below background levels of copper in the river, based on the available data it had -gath-l ered at that time. Subsequently, the state regulatory agency l l informed the applicant that it would reconsider the restrictive . copper limitation and modify the existing discharge limitation if the applicant could demonstrate on the basis of new scientific evidence and technical information that a higher level of copper discharge would not result in any adverse ef fect on the aquatic biota of the receiving waters in order to comply with the state's criteria on toxic substances. To support its case, the applicant conducted a number of physi-cal, chemical and biological studies. The reason for this ap-preach was that the applicant realized that there was growing l l l evidence that the potential for tqxicity of trace metals, in general, at a specific site was strongly influenced by site l conditions, such as those decribed Exhibit 3. The studies in- [ cluded: (1) physical modeling of the river in the vicinity of l
the discharge; ( 2) monitoring of the background levels of cop-f' [ per and other trace constituents in the_ proposed makeup water source; ( 3) chemical determination of the different forms and distributions of copper in the aquatic environment; and (4) conducting bioassays utilizing waters from the vicinity of the site and local species of salmon and trout. The results of these studies were then presented at a second round of NPDES public hearings. , Based on its studies, the applicant proposed a discharge con- ' centration of 50 ug/l for long-term operation and 100 ug/l dur-ing the first six months of operations (Exhibit 12) . The rea-son for the two numbers is because corrosion rates were expec-ted to be highest during start-up operation and gradually di-minish during long-term operation. Investigations were conduc-ted to estimate these corrosion rates under varying plant oper-ating conditions. The applicant's selection of 50 ug/l as a discharge concentra-l tion on copper - for long-term operation was based on the follow-l ing lines of evidence (Exhibit 13) : 1 i 1. A background concentration of 7 ug/l total copper could be expected in the makeup water supply based on weekly sampling for a year at several stations along the river.
- 2. A concentration of 13 ug/l was estimated to be a " safe concentration" in the river. This figure was derived from laboratory bioassays utilizing waters from the site and various species of juvenile salmon and trout.
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- 3. Physical modeling of the river indicated that the out-fall design could conservatively achieve a 10 fold di-lution from the point of discharge to the edge of the mixing zone 50 feet wide and 100 feet long.
- 4. With a " safe concentration" or concentration that would comply with the water criteria for toxic sub-stances within the receiving water body and background concentration of 7 ug/1, the applicant calculated that a concentration of 70 ug/l at the point of discharge could meet a concentration of 13 ug/l at the edge of the mixing zone.
A number of intervenors, including two state agencies which have responsibilities for aquatic resources argued for a receiving water quality standrrd of 5 ug/l total copper, that is, outside the mixing zone. They chose 5 ug/l because there was evidence in the literature that this low level had little or no effect on the down-stream migration of juvenile species of salmon. Since the 5 ug/l value was below the background levels of copper shown to be present in the receiving waters (7 ug/1), any estimation of discharge concentrations, even a water quality-based one, would certainly be below those . suggested by the applicant. The state regulatory agency, based on the findings of facts of the Hearing Examiner, took an intermediate position and is-sued a modified NPDES permit limiting the discharge of copper in the blowdown to 30 ug/l for long-ter.n operations and 65 ug/l for short-term operation. It based its decision on projected levels of copper in the discharge lower than those projected by the applicant but levels it believed would be protective of the aquatic resources in the river. In effect, the discharge concentration was water j quality-based requiring the plant to meet water quality l standards at the edge of the mixing zone. While this limitation is more restrictive than the one proposed by the applicant, it was certainly greater than the one in the earlier permit. The latter would have compelled the owner to discharge l copper at concentration less than that observed in the river even at the point of discharge. r
IV - LESSONS LEARNED Based on the discussions . presented in the preceding sectTon, especially the case studies, the following lessons can be learned:
- 1. The utility industry will be experiencing some uncer-tainties over EPA intention as indicated in its ANPRM, to provide a list of pollutants for which water quality, standards must be developed by the states or EPA. The implication of a move to promulgate such a policy could have a significant impact on discharges of pollutants such as copper. For example, based on the proposed criteria f or copper on both f reshwater and salt water environments, even taking hardness in to consideration many utilities with existing generating units containing copper alloy tubing or future units contemplating the use of copper would be hard-pressed to meet water quality standards. Based on the pro-posed criteria particularly, the background levels in many natural water bodies already exceed the levels
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stated in the criteria. l l
- 2. With respect to the use of the proposed water quality criteria for water quality-based effluent limita.tions each discharger should be cognizant or take into ac-count scientific considerations specific to a given water body. Site-specific factors such as pH, te mpe r -
ature, chemical constituents and other factors may re-l duce the toxicity of certain compounds. For examples, the safe concentration of copper determined in Case C, 13 ug/1, is higher than the level one would expected on the basis of hardness alone, as the proposed water quality criteria for copper would suggest. Based on the proposed water quality criteria and a hardness of
...r_- . - -, . . _.. . . - . . - . . . _ _ , _ _ . . ,
20 mg/1, a safe concentration of 1 ug/l would have been expected. However, the waters in Case C contained ad- ^ ditional complexors which reduced the toxicity of cop-per. Therefore, utilities might be expected to conduct studies at specific sites to estabiish this point for certain pollutants.
- 3. There will be a shift from the technology-based efflu-ent limitations to water quality-based discharge limi-tations for certain toxic pollutants. Even though EPA may or may not develop toxic pollutant effluent limi-tations on these pollutants, states with NPDES permit authority n.ny impose more stringent limitations based on water quality standards.
- 4. The electric utility can expect the unexpected when it comes to toxic pollutants. Substances that presently are not included on the present list may be listed at some future date. The experience from the above case studies,particularly Case A and C, would indicate that the individual utility may not always be prepared to expect intervenors, especially from state regulatory rgencies, to challenge discharge specific toxic pollu-tants.
- 5. During environmental licensing of any future facili-ties utilities should make every effort to have the appropriate personnel be aware of or at least obtain an inventory of all potential toxic pollutants that may be discharged.
REFERENCES j
- 1. Alexander, J E, 1973. Copper and Nickel Pickup in the Cir-culating Water System at Northport. Long Island Lighting Company, New York.
E~F, 1974. The Discharge of
- 2. Compton, K G and Corcoran, Copper Corrosion Products f rom Steam Electric and Desalina-zation Plants and its Ef fects on the Nearby Ecosystem. In-ternational Copper Research Association. Final Report, June 1, 1974.
- 3. National Academy of Sciences,1977. Copper-Committee of Medical and Biological of Environmental Pollutants. Na-tional Academy of Sciences, Washington, D C.
- 4. National Academy of Sciences, 1977. Drinking Water and Health. National Academy of Sciences , Washington, DC.
- 5. Roosenburg , W H, 1969. Greening and Copper Accumulation in the AmericanOyster, Crassostrea virginica, in the Vicinity of a Steam Electric Generation Station. Chesapeake Science l
l l 10:241 US EPA 1976. Quality Criteria for Water. U S Environmen-6. tal Protection Agency.
- 7. US EPA 197 8. Draf t Technical Report for Revision of Steam f
j Electric Effluent Concentration Guidelines. t Ambient Water Quality Criteria - Copper. US
- 8. US EPA 1979.
Environmental Protection Agency.
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, i EXHIBIT 1 COPPER IN POWER PLANTS Use in Material
. Condenser Tubes
. Boiler System
. Piping and. Values
. Pumps
. Sealants and Joint Compounds i
Chemical Additives
. Scale and/or Corrosion Control
. Biocides Liquid Discharaes
. Corrosion and Erosion Products from Once-through Cooling System
. Corrosion and Erosion Products from Cooling Tower Blowdown
. Chemical Additives
. Boiler and Boiler Tube Cleaning Wastes
. Boiler Blowdown
. Fly Ash and Bottom Ash Transport Water
. Low Volume Wastes E . _- _ _ . . _ _ _ - . . __ __ - _ _ _ . _ _ . - . _.. _ _ _ _
EXHIBIT 2 OCCURRENCE OF COPPER IN THE AQUATIC ENVIRONMENT Ambient Levels in Surface Waters
. Mean Concentration in 1600 Waters Surveyed in the United States is About 15 ug/l
. Mean Levels for Different Drainage Basins in the United States Ranged from 7 to 27 ug/l
. Waters in the Pacific Northwest Averaged about 9 ug/l With a Range of 1 to 37 ug/l Sources of Copper
. Rocks and Minerals
. Industrial
- Sources
. Agricultural and Forestry Products
. Foods
. Sewage Treatment Plant Effluent
. Combustion of Fossil Fuels
. Corrosion Product from Water Distribution Systems i
. Corrosion Products from Steam Electric Power Plants l
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. - _ - - . _e - . -,_.
_ . . . , , , , , . , , _ _ . - . . _ _ . _ -._,__ _ , .-,,,._-_,...-.__s., , -.-m__ _ - . _ _ - , , _..
e
! EXHIBIT 3 CHEMISTRY OF COPPER IN THE AQUATIC ENVIRONMENT GENERALIZED SCHEME OF DISTRIBUTION OF COPPER SPECIES IN AGUATIC SYSTEMS TOTAL l
I I SOLUBLE PARTICULATE FREE, IONIC COPPER LOOSELY-BOUND TO SURFACE OF PARTICLE LABILE COPPER LOOSELY-BOUND IN SOLUBLE COMPLEXES COPPER TICHTLY-BOUND COPPER INCORPORATED IN SOLUBLE COMPLEXES INTO PARTICLE l BOUND COPPER TIGHTLY-BOUND TO SURFACE OF PARTICLE
- Chemical and Physical Factors Play an Important Role
! in Controlling the Form and Availavility if Copper
- Small Percentage of Total Copper is in the Ionic Form, Probably Less Than 10% of the Total
- The Presence of Inorganic and Organci Chelators or Complexors is Largely Responsible for This Behavior
l . EXHIBIT 4 ACUTE AND CHRONIC VALUES FOR COPPER Freshwater Acute Values Salmonids 17 - 100 ug/l (Sof twaters) 7-100 ug/l (Ha,rdwaters) Other Freshwater Fish 50 - 500 ug/l (Softwaters) 500 - 1000 ug/l (Hardwaters) Invertebrates 20 - 1,700 ug/l Chronic Values Salmonids 3 - 100 ug/l (Sof twaters) 1 Freshwater Fish 4- 40 ug/l (Softwaters) ' Invertebrates 4- 15 ug/l (Sof twaters) Marine Acute Values Fish 38 - 510 ug/l Invertebrates 9 - 600 ug/l I i Chronic Values l i Invertebrates 38 - 77 ug/l l l l l l .
4'. 9 4 EXIIIBIT 5 COPPER EFFLUENT LIMITATIONS FOR STEAM ELECTRIC GENERATING SCOURCES I l i I BPT BAT NS PS . (ag/1) (mg/1) (mg/1) Effluent Sources Avg Max Avg Max _ Avg Max - i Once Through Cooling Water - - - - - - Cooling Tower Blowdown - - - - -(2)' _(2) Bottom Ash Transport Water - - - - - Fly Ash Transport Water - - - - - - l l Metal Cleaning Waste 1.0 1.0 1.0 1.0 1.0 1.0 Boiler Blowdown 1.0 1.0 1.0 1.0 1.0 1.0 Low Volume Waste Sources - - - - - - l l l \ (1) The (daily) quantity of pollutant discharge shall not exceed the quantity determined by multiplying the (daily average) flow times the concentration listed in the table. (2) No detectable amount of corrosion inhibitors. l l 1
EXHIBIT 6 BOILER BLOWDOWN, RAW WASTE CONCENTRATION (1) Pollutant Name No. of Points Mean Concentration (mg/l) Copper 258 0.14 Iron 273 0.53 Oil and Grease 151 1.74 Phosphorous 19 17.07 Suspended 230 66.26 (1) USEPA (1978) . Draf t Technical Report for Revision of Steam Electric Effluent Concentration Guidelines.
4 EXilIBIT 7 i i EXAMPLES OF STATE WATER QUALITY STANDARDS FOR COPPER } Delegated i NPDES State Authority Water Use Standard or Criterion Alabama No . Freshwater Aquatic Life None Alaska No Freshwater Aquatic Life 0.01 x 96 Ilt LC 50 as determined through continuous bioassay for life stage of' species most sensitive thiologically important to the location or criteria cited t ! in the " Red Book" Arizona No Freshwater Aquatic Life 0.05 mg/l Colorado No Freshwater Aquatic Life Numerical limits a function of hardness e.g.: 0.01 mg/l - harndess of 0-100 0.04 mg/l - hardness of 400 plus l Florida No Fish and Wildlife 0.5 mg/l or toxic substances free from substances attributable to
. Other discharges in concentrations or combinations which are toxic or l
harmful' to human, animals or aquatic t life. 111'nois No Freshwater Aquatic Life O.C2 mg/l l
i . EXIIIBIT 7 EXAMPLES OF STATE WATER QUALITY STANDARDS FOR COPPER > (Con t d ) ] N PD ES State Status Water Use Standard or Criterion
- Maryland No Water Recreation and Free from toxic substances in Aquatic Life; Natural concentrations or combinstions Trout Waters which interfere directly or indirectly with water uses, or which are harmful to human, animal,
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plant,or aquatic life. Michigan Yes Freshwater Aquatic Life 0.1 x 96 hr LC 50 or other appropriate effect end points
- obtained by continuous flow or in situ bioassay using suitable test organisms Ohio Yes Warm Water. Habitat Numerical values a function of i
hardness e.g.: 0.005 mg/l at hardness 0-80 0.010 mg/l at hardness 81-120 0.085 mg/l at hardness 301-320 Cold Water Habitat 0.005 mg/l Washington Yes Freshwater Salmonid Toxic material concentration should Fisheries be below those of public health significance or which may cause
- l. , acute or chronic toxic conditions to aquatic biota, or which may
\ adversely af fect any water use.
e t EXHIBIT 8 CRITERION FOR COPPER l l' Reference Water Use Criterion Red Book (1976) Freshwater and Marine 0.1 x 96 hr LC 50 as determined Aquatic Life through nonaerated bioassay using a sensitive aquatic indigenous species Freshwater Aquatic Life 24 hr average copper concentration Draft Water Quality Cri- = e(0.65.ln (hardness) - 1.94) teria for 65 Maximum copper concentration Toxic Pol- = e(0.88.In (hardness) - 1.08) lutants Salt Water Aquatic Life 24 hr average copper concentration
= 0.79 ug/l ,
maximum copper concentration
= 18 ug/l i
e e
l EXHIBIT 9 COPPER CRITERION TO PROTECT FRESHWATER AQUATIC LIFE 20.o - 24-HOUR AVERME COPPER CONCENTRATION VS. HARDNESS so.o -
!iP s
4.o -
- o. +e U 'iii li*
y 9
/
d'/ l0
= .-
N / j 0.4 -' O.2 10 20 m 2m MO TOTAL HARONESS (mg/l) In secte
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EXHIBIT 10 COPPER CRITERION TO PROTECT FRESHWATER AQUATIC LIFE 10 0.0 MAXIMUM CDPPER CONCENTRATION VS. HARDNESS
/
o+ 40.0 - b' 5 s
.E f g 20.0 - 9.,
E 5 kHi - 8 W io.o b 2_ 4D -
/
il2 2 l 2.o - i 1.0 ' ' ' ' s l 10 20 40 10 0 200 400 TOTAL HARDNESS (mg/1) in scale l
c - . EXHIBIT 11 CASE STUDIES ON COPPER AT POWER PLANTS Case A Case B Case C Site West Coast East Coast Pacific Northwest . Closed-cycle Clos ed-cycle Cooling System Once-through Condenser Copper-nick el- Copper-nickel Copper-nickel Material Issue
^
Suspected shell- Concern over Concern over fish kill potential ef- potential ef-feet on feet on aquatic aquatic resources resources l Outcome Replacement of Unresolved al- Replacement of condenser though regu- condenser i material by latory agen- material by titanium cies indi- stainless steel; cated a pref- water quality-erence of a based discharge of a substi- limitation on tute material cooling tower blowdown l I
i *s EXHIBIT 12
SUMMARY
OF POSITIONS ON COPPER DISCHARGES APPLICANT 100 ug/l During first.6 months and 30 days after each shutdown 50 ug/1 During long-term operations. INTERVENORS 5 ug/l as a water quality standard, i.e., outside the mixing zone REGULATORY AGENCY 65 ug/l During first 6 months and 30 days af-ter each shutdown 30 ug/l During long-term operations
t * ' O e EXHIBIT 13 COPPER CONCENTRATIONS IN THE RIVER (BASED ON BACKGROUND LEVEL OF 7 ug/1) DISCHARGE CONCENTRATION CONCENTRATION 10: 1 DILUTION (ug/1) (ug/1) g---------------------------- 1 1
! 18 100 I 8
b a
- MIXING ZONE l N I o !
O I I 70 8 13 1 1
.J --------- J 100 FEET y 4
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.einvirotphon]
Curn?8'N UNDERGROUND WATER INTAKE FOR NUCLEAR PLANT UILL PROJECT THE ENVIRONMriT by Joseph H Kenny, Envirosphere Company, a Division of Ebasco Services Incorporated, 21 West Street, New York N Y 10006 by Kenneth R Wise, Washington Public Power Supply System, 3000 George Washington Way, Richland, Washington 99352 The production of electric energy from power plants demand I l l large volumes of cooling water. Large volumes must move into and through a power plant on a constant basis to dissipate the heat even when facil-ities include cooling towers. Sites for power generation plants must be located on or near a reliable source of cooling uater that will be available for a continuous period of 40 to 50 years. Conscientious environ-mental protection of our nation's resources calls for reasonable action ' to minimize environmcatal impact wherever possible. Such considerations for protecting the environment have been realized by the Washington Public Power Supply System (WPPSS) in developing the design for their nuclear power plant site on the Chehalis River in western W'shington. a The preferred location for this first nuclear plant in western Washington is on one of the many salmon spawning streams of the Pacific Northwest. The power plant will require a maximum flow of 36,000 gal / min (gpm) (80 cu ft/sec) from the Chehalis River. A traditional
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- cnvirasphera 2 cempony river intake structure could readily supply this amount on a continuous basis. However, to avoid the possibility of fish mortality and impinge-ment which can occur at this type of river intake, the Supply System has j elected to taba advantage of the hydrogeologic conditions of the Chehalis River Valley by installing a subsurface (underground) water intake system.
Such hydrogeologic conditions consist mainly of a thick, permeable uncon-solidated aquifer underlying the alluvial river valley I) . The unconfined aquifer is recharged from river flow whenever the ground water levels are i lowered due to excess pumping or drought periods. By the principle of
" induced infiltration,"I ) pumping from either a horizontal collector system or a vertical well system will permit the flow of 80 cfs of river water to i
l enter the aquifer and-then be pumped to the power plant via a pipeline. Loss of some species of the river's aquatic life could be minimized by the use of a specially designed surface intake structure, but such a ' design could cost on the order of twice the $3 to $4 million for a subsurface intake system which will more assuredly eliminate damage to the aquatic environ-ment.
- . - - , _ . - . , . , , . . - _ . - . - - - - - - . -- .- ., , _ . , , ~ -
~ - _ -
envirftphsro esmpany 3 4 In order for the principle of induced infiltration to be efficient, an aquifer must be located near a surface source of water such as a river, lake or ocean. When the hydrostatic pressure or water level in the aquifer is lowered by pumping, a hydraulic gradient or slope occurs between the surface and the water level in the aquifer. This differential will result in a flow from the river to the equifer to replace the water produced by pumping. When pumping continues long enough, a steady-state flow condition will result in which most of the pumped water will be derived from the surface source. Actual yield will depend largely on the hydraulic conductivity (transmissivity) of the aquifer and the infil-tration rate of the riverbed. After long pumping periods, a small amount i of drawdown such as those observed at the site in Washington help to confirm that a large yield is possible due to the high rates of hydraulic conduc-tivity in the streambed and aquifer. Variations in river stage and temperature will also affect the I) Hydrologic analysis yield of an aquifer recharged by induced infiltration . l l l
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------r- w
cnvirciph:ra 4 c:mp ny must include these variables to confirm that during periods of extreme low stage of the river coupled with maximum temperatures will not affect the desired yield. Data from controlled pump test progrsms serve as a basic guide for the analysis of expected conditions at a specific site. Extensive test data have confirmed that the Chehalis River will be a ' reliable source during extreme low flow and maximum temperature conditions. Sparse hydrogeologic data for the Chehalis River Valley indicated I4) that some ground water could be obtained from the valley aquifers . i Aquifer charactersitics such as the coefficients of permeability, trans-missivity and storage were not available to ascertain a definite volume for a long-term withdrawal in the plant site area. Also unknown was the amount of hydraulic conductivity which existed between the riverbed and the ground water aquifer. Within one mile of the plant site, early testing of the aquifer ar the confluence of the Satsop and Chehalis Rivers by the Ranney Method , Western Corp of Kennewick, Washington, in conjunction with the Story & Armstrong Drilling Company, developed new data to confirm that conditions j __
cnvirriphro 5 c:mpany [ l were ideal to allow the use of a subsurface intake system to produce a reliable flow of cooling water. At this location, the aquifer pump -- l test program confirmed a transmissivity of 1,240,000 gals per day /ft, the permeability as 30,000 gals per day /sq ft at a test temperature of 51 F . Since the line source of reenarge was the nearby river, the coefficient of storage was unimportant. Recharge from the river to the Not aquifer occurred within 20 minutes during the pump test program. only is the aquifer highly capable of producing the required flow, but the tests also proved that the hydraulic conductivity between the river bottom and the aquifer is excellent. Further testing was carried out three miles downstream from the site along the Chehalis River when an even thicker aquifer was
' encountered during a controlled pump test program by Robinson & Noble, Inc, Consulting Hydrogeologists of Tacoma, Washington in conjunction with i
the Story & Armstrong Drilling Company. Up to 180 ft of water saturated l material could be utilized for design purposes of the proposed sub-surface intake system. Data from the pump test program was used to _ . - . >e**' e- g- - .w.- ,,.m7. . - - - . . ep- . _ .-c_,,. g.-- --.. -r, _ - , , ,, , , . - - _ . .. <
' envirr:ph:ro 6-c:mpany calculate the transmissivity which ranges from 720,000 gals per day /ft up to 1,150,000, gals per day /ft at 50 F to 7,000 gals per day /sq ft.
The test program also supplied data for determining the average infil-tration rate of the Chehalis River at this location which ranged from 3.97 gals per day /sq ft of head loss to 6.20 gals per day /sq ft of - head loss ( ). Hence, the aquifer and streambed conditions confirm that hydrogeologic conditions are especially favorable for utilizing the j principle of induced infiltration at this location along the south side of the Chehalis River. Even though the transmissivities and permeability rates of the aquifer at d21s location are less favorable than the pre-vious test area, the extra thick aquifer is a much more favorable factor for maximum yield. The calculated yield is several times greater than the required flow for the power plant, The principle of induced infiltration for water supply is not a new or unique method for industrial water purposes. It is utilized in many areas throughout the U S and Europe for industrial and municipal L water supplies where large daily volumes are required. At this
. - - - en
^
w-,e
, envirosphsro -7 crmpany I
particular site in western Washington, the test data has shown that induced infiltration can be utilized with either a horizontal col-1ector system or a vertical well system. A horizontal collector j system would locate the pumps in a concreta caisson along the shores of the river with the caisson extending to approximately a depth of-100 ft. At the bottom of the caisson, the horizontal collector screens would radiate from the caisson outward below the river bottom. Two or three caissons at a spacing of 1000 ft would be required for this particular site. The final number of caissons and pumps will depend on the amount of water supply required by the Supply System i for plant operation and safte> measures'. j A vertical well system may also be utilized for the induced l infiltration of river water into the aquifer. Submersible pumps wou:d transfer the water to the power plant site via pipeline. The wells will be spaced about 200 ft apart and will penetrace the entire aquifer with well screens. The proposed number of wells ranges from 16 to 24 at this time. The ultimate number will also depend on the requirements of the Supply System for their plant operating and safety conditions. i y w m= ~ - ' .q. - '
*m --
- r - e---w- -
- cnvir$sph:ra 8 cmpany Either system will assure minimal adverse impact at this site. The utilization of a subsurface intake system will pre-vent any damage to the river's aquatic life and little impact upon the land surface at the intake area along the river bank. In terms of the environment, the use of a subsurface intake system permits the viability of this site with its reliable supply of high quality cooling water. An alternative intake structure, such as that normally used for power plants is a surface intake system constructed of con-crete and steel. Environmental concerns would require special baffles and hydraulic controls for ene movement and protection of sensitive aquatic life. Such an alternative structure would not only be more costly than the two systems described here, but would not assure elimin-ation of impact upon the aquatic ecology of the river.
Another advantage of the subsurface intake is that the water l quality will be superior in almost every aspect ( ' 0) . The induced infiltration method of obtaining water provides an effective filter mechanism. The total dissolved solids are expected to be considerably lower as pumping progresses during plant operation. Prior to use in the recirculating system, water treatment, of any type will be unnecessary. 2
'cnvir:Iphara ccmpany . 9 A maximum withdrawal of 80 cfs from the Chehalis River will also have a minimr1 impact upon the river when using a sub -
surface intake system. Hydro'.ogical analysis of low flow and low tide conditions, which occur ou the ch'ahalis Rive due to its prox-imity to Grays Harbor and the Pacific Ocean, show that an 80.cfs withdrawal will effect the river stage less than .2 of a foot. The induced flow from the river into ground water will extend over an area of 10,000 ft along the river bottom. The flow velocity of the water entering the aquifer will be at .00015 of a ft/second at the riverbed. Hence, the impact upon the aquatic environment will be negligible.. l Impact upon ground levels will be restricted to a maximum I drawdown of 26 ft in the center of the pumping area. At a distance of 3000 ft up and downstream, the drawdown will be less than six inches under the extreme conditions of low flow and low tide in the Chehalis River.
~ w - e m w - e
,_a a __ _ -
^
i t
- chwirfsphsro 10 c:mporty Induced infiltration, as stated previcusly, is not new in its application to industrial water supply systems, but it is unique for power plant sites. The application of induced infiltra-tion for a subsurface intake water system at the the Satsop site is believed to be one of the first for a power plant in the U S.
Where hydrogeologic conditions permit, protection of the environment makes it a desirable alternative for a power plant water supply.
* [nvidsphiro ecmpa J
- LITERATURE REFERENCES
- 1. Eddy, Paul A, 1966, Geology and Ground Water Resources of the Lower Chehalis River Valley, W'ter a Supply Bulletin No. 30, State of Washington, Division of Water Resources.
- 2. Walton, William C, 1962, Selected Analytical Methods for Well and Aquifer Evaluation. Illinois State Water Survey Bulletin No. 49.
- 3. Mikels, Frederick C and Klaer, Fred'H, 1956, Application of Ground Water Hydraulics to the Development of Water Supplies by Induced Infiltration, Publication No. 41, Association of Inter-nationale d'Hydrologie, Symposia Darcy, Dijon.
- 4. Robinson, John W and Norbisruth, Hans, 1966, Results of Test Drilling for a Ground Water Supply in Lower Chehalis River Valley, Washington, Robinson, Roberts & Associates, Tacoma, Washington (unpublished report).
- 5. Mikels, Frederick C,1974, Report on Ground Water Study for Ebasco Services Incorporated, WPPSS Nuclear Project No. 3, Satsop Washington (unpublished report).
- 6. Noble, John B,1974, Feasibility of an Infiltrated Grottnd Water Supply from Chehalis River near Montesano, Washington (unpublished report).
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