ML18213A432
| ML18213A432 | |
| Person / Time | |
|---|---|
| Site: | Turkey Point  |
| Issue date: | 07/18/2018 |
| From: | Hefty L N Miami-Dade County, FL, Dept of Environmental Resources Management |
| To: | Atomic Safety and Licensing Board Panel |
| SECY RAS | |
| Shared Package | |
| ML18213A417 | List: |
| References | |
| License Renewal, RAS 54382, 50-250-SLR, 50-251-SLR | |
| Download: ML18213A432 (61) | |
Text
Attachment Department of Regulatory and Economic Resources Environmental Resources Management 701 NW 1st Court, 4th Floor Miami, Florida 33136-3912 T 305-372-6754 F 305-372-6759 miamidade.gov MIAMI-DADE COUNTY Carlos A.Gimenez, Mayor July 18, 2018 Lea Crandall, Clerk of the Department Office of General Counsel Florida Department of Environmental Protection 3900 Commonwealth Boulevard Tallahassee.
Florida 32399-3000 CERTIFIED MAIL NO 7001 2510 0001 1765 4022 RETURN RECEIPT REQUESTED Timothy Rach, Program Administrator Submerged Lands and Environmental Resources Coordination Program Florida Department of Environmental Protection Bob Martinez Center 2600 Blair Stone F:oad MS 2500 Tallahassee, Florida 32399-2400 CERTIFIED MAIL NO 7001 2510 0001 1765 4176 RETURN RECEIPT REQUESTED Re: Request for an Extension of Time in accordance with Section 120.57, Florida Statutes regarding Florida Power&Light (FPL)Permit No.0193232-182, Everglades Mitigation Bank Phase II Modification and Credit Release dated June 28, 2018, for FPL facilities located in southern Miami-Dade County approximately 6 miles southeast of Florida City and Homestead, Between US Highway 1 and Card Sound Road, in Sections 5-8, 18, 19 and 28-33 in Township 58 Range 40 East;Sections 20-22, 25-29 and 32 36 in Township 58 South, Range 39 East;Sections 1 and 2 in Township 59 South, Range 39 East;and Section 6 in township 59 South, Range 40 East, Unincorporated Miami-Dade County, Florida.
Dear Ms.Crandall and Mr.Rach:
On June 28, 2018, Miami-Dade County Division of Environmental Resources Management (DERM)received via email the Florida Department of Environmental Protection (FDEP)letter issued June 28, 2018 regarding Florida Power&Light (FPL)Permit No.0193232-182, Everglades Mitigation Bank Phase II Modification and Credit Release.The subject permit modification"updates specific conditions based on recent data received to clarify the amount of freshwater Everglades Mitigation Bank Phase II (EMB 2)receives south of the L-31-E levee, allows for incremental vegetative success credit releases, and releases 98.55 freshwater herbaceous credits." Furthermore, FDEP has required the permittee to lower the control elevation of the Everglades Mitigation Bank culvert weirs from 2,2 feet to 1.8 feet NGVD within 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> of issuance"to assure that the area south of L-31-E is receiving appropriate amounts of freshwater flow..." The purpose of this letter is to respectfully request additional information and clarification from FDEP on this action, and to hereby request a sixty (60)day extension of time to September 17, 2018 for DERM to further review and fully evaluate FDEP's action in this matter in order to contemplate action regarding a petition for an administrative hearing in accordance with Section 120.57, Florida Statutes.!betiverht:e Epccttitnct Every"bay Page 2 of 5 Over the past several years, DERM has been working with FPL on concerns over water quality impacts associated with the FPL Turkey Point Cooling Canal System (CCS).On October 7, 2015, FPL entered into a Consent Agreement with DERM to address these water quality impacts.The Consent Agreement identified various remedial actions and hydrologic improvement projects that FPL was required to undertake to address water quality impacts, including one such requirement that FPL increase the Everglades Mitigation Bank culvert weirs elevation to no lower than 0.2 feet below the 2.4 foot NGVD trigger of the S-20 Structure.
This condition was included in the Consent Agreement because of concerns associated with the impacts of the hyper saline plume emanating from the CCS on water resources in the area.The FPL Turkey Point CCS, as well as FPL's Everglades Mitigation Bank are located in the extreme southeast region of the county in an area that is experiencing significant westward migration of the salt intrusion front at the base of the Biscayne aquifer, and where historically fresh surface water canals have recently been documented with higher conductivity and chloride levels uncharacteristic of fresh water bodies.Miami-Dade County is concerned that the subject modification, as issued, establishes operating criteria for the EMB2 culvert weir elevations and target water deliveries that: may result in adverse impacts to water resources upstream of this area;and that are not sustainable over the long term, particularly as it relates to existing inland migration of the salt intrusion front in this area, which is expected to be further exacerbated by sea level rise.The following describes some of DERM's concerns regarding the aforementioned subject permit modification:
1.Upstream Water Levels and Salt Intrusion a.The DEP-mandated control elevation of 1.8 foot NGVD is 0.6 feet below the current drainage trigger elevation at the adjacent S-20 water control structure.
DERM is concerned that setting the control elevation at 1.8 feet NGVD is not sustainable from a water management perspective.
The stage in the L-31 E canal is dependent on the setting of the adjustable weirs in these 40 culverts.The decision to modify the permit and set the culverts to 1.8 feet will cause the water levels in the L-31 E canal to drain to this elevation.
In addition, the wetlands in the Model Lands Basin will be drained by the L-31 E canal whenever the stage in the upstream wetlands exceeds the DEP mandated 1.8 feet NGVD control elevation of the canal.This drainage has and will continue to undermine the ecological functioning of the wetlands upstream of the L-31E, including wetlands that are part of the mitigation bank.b.The EMB 2 is located east of the salt intrusion line, as delineated by the 1000 ppm isochlor at the base of the Biscayne Aquifer.The salt front migrates westward (inland)in this area when water levels upstream of the L-31 E are insufficient to prevent this salt intrusion, therefore, water management in the bank and the surrounding basin is critical for preventing the landward migration of the salt front, towards potable water wellfields in the Homestead area, including the Florida Keys Aqueduct Authority wellfield that provides drinking water for the Florida Keys and Miami-Dade County's Newton wellfields.
Attachment 1 demonstrates how low the surface and groundwater levels can fall in this basin which is drained by the EMB 2 culverts.It is notable that during some drought years, the groundwater levels in this basin can fall below sea level in the area upstream of the L-31E.c.The most recent USGS study indicates that the current average rate of landward migration of the saltwater interface in the groundwater is at 140 meters per year and that the salt front now extends beyond monitoring well cluster TPGW-7 of the FPL Turkey Point Uprate Project.This study supports the conclusion that the groundwater salt front in this basin has been advancing upgradient towards the aforementioned public wellfields and private drinking water wells as a result of unsustainable water management practices; this includes the removal of more water from this basin than it receives via rainfall.A copy of the aforementioned USGS study is provided as Attachment 2.It should be noted that the saltwater front is currently located more than 6.5 miles inland at the northern boundary Page 3 of 5 of the basin and more than 10.6 miles at the SW boundary of the basin at the 1000 ppm isochlor line.An illustration of this saltwater front is provided in Attachment 3.d.The extent to which the L-31 E Canal (which historically was a freshwater canal)can be protected from saltwater contamination is dependent on the stage of the canal.Attachment 4 depicts the recent extent of chloride contamination of this canal.It should be noted that the L-31 E canal is connected to upstream secondary canals including the Model Lands South canal, therefore chloride impacts observed in the L-31 can now become a potential surface water pathway for further chloride contamination of the secondary canal system as well.Attachment 5 depicts the locations in the secondary canal where elevated conductivities have recently been detected.Attachment 6 includes a meeting presentation with information on the hydrology of the Model Lands basin and how the basin is impacted by FPL's water management operations.
Attachment 7 summarizes salinity increases in the L-31 E over the Uprate Project monitoring period of record, demonstrating the high degree of salinization that has occurred in these surface waters.The water quality of the L-31 E was initially freshwater and salinities during the period of record have increased to over 29 PSU.e.DERM has considered the cumulative impact of water losses from the Model Lands Basin with the permit-mandated minimum annual flows through the culverts, given other water losses from this basin and nearby areas.These include the losses associated with operation of the Interceptor Ditch (ID)pumps and the groundwater recovery well system (which is now operational).
As an example, the flows mandated in this permit modification in combination with the recovery well system will result in more than 20,000 acre-feet of water lost from this area annually.This is the equivalent of more than one foot of surface water across the entire Model Lands wetlands and does not include other permitted water losses such as those associated with replacement of water from operation of the ID pumping into the cooling canals pursuant to the authority granted under the Fifth Supplemental Agreement with the South Florida Water Management District.It is also not clear if FDEP has considered the increased pumping losses that are expected from the ID operations since the stage triggers for the ID pumping have not been modified and since lower water levels in the L-31 E Canal in relation to cooling canal stage is the condition that triggers the operation of the ID pumps.2.Comprehensive Everglades Restoration Plan (CERP)Consistency a.A control elevation of 1.8 feet NGVD is not sustainable or consistent with Everglades restoration in this area including the restoration envisioned under the C-1 1 1 Spreader Canal Phase One CERP project.In order to restore more natural hydroperiods and stages to the wetlands in the Model Lands basin, this CERP project calls for a control elevation much higher than the 1.8 foot elevation mandated in the DEP permit modification.
Please refer to the C-1 1 1 Spreader Western Project implementation report for further information relating to this CERP project.Under this CERP project, the adjacent S-20 water control structure will be operated at a 2.9 foot NGVD open trigger when the approved trigger changes are fully implemented, and the structure will close at an elevation not lower than 2.4 feet NGVD.A series of hydrographs depicting the aforementioned concept is provided as Attachment 8.In the absence of new water sources, this attachment helps to illustrate the concern that water levels in the Model Lands wetlands will not likely be able to reach the 2.9-foot CERP open trigger stage during typical (or even wet)water years based upon the DEP-mandated culvert control elevation.
Therefore, setting the culvert weirs at the 1.8 foot control elevation will drain the water above this elevation through these culverts and, as a result, will prevent most or all of the hydroperiod and stage benefits to the Model Lands that were envisioned with the CERP S-20 operations change.In order to preserve the ability of the CERP S-20 operations change to provide stage and hydroperiod benefits (as well as salt intrusion prevention benefits), the water levels in the L-31E canal should be held to canal stages of 2.4 feet or higher as approved by CERP.This CERP restoration strategy to operate the S-20 structure at a 2.9-ft NGVD open trigger has been authorized by FDEP through Page 4 of 5 issuance of FDEP permit number 0293559-011; however, FDEP's recent permit modification to order lowering of the FPL culvert gate elevations is inconsistent with this CERP restoration strategy and negates it.FDEP's action appears inconsistent with the CERP S-20 operations change, and also appears inconsistent with the Army Corps permit for construction of the FPL Everglades Mitigation Bank (SAJ-1 995-1 55(IP-TKW)), which states"This permit does not authorize interference with any existing or proposed Federal projects." 3.Miami-Dade-owned and other Conservation Lands a.Public conservation lands, a significant portion of which are owned by Miami-Dade County's Environmentally Endangered Lands Program, are located upstream of the culverts in the Model Lands Basin and are affected by competing freshwater needs.State and Federal agencies have recognized the need to restore more natural hydroperiods in this area as per the numerous CERP projects designed to restore wetlands in this specific area.The reset of the culvert weirs back to 1.8 feet NGVD as per the permit modification will serve to further drain and adversely impact these Miami-Dade County-owned conservation lands.Additionally, hydrologic impacts including salt intrusion and groundwater and surface water contamination have been documented on these lands.A map depicting the results of recent sampling that reveal water quality impacts to surface waters within these publically-owned wetlands is provided as Attachment 9.Evidence based on recent sampling indicate that saline water has entered the secondary canal from the L-31 E Canal.An illustration of the extent of the saline groundwater plume from the cooling canal system on these Miami-Dade County-owned conservation lands, based on tritium tracer contours, is provided as Attachment 10.4.Methodology for Release of EMB Wetland Mitigation Credits a.As a regulatory agency that accepts State permitted mitigation banking credits, DERM is concerned about the manner in which the determination that a credit release was appropriate and how the calculations reflected in the credit release schedule were completed.
The modification of the permit and credit release appears inconsistent with the findings of the FDEP inspection report dated March 21, 2018.Specifically, It appears that EMB2 was requesting a partial release of 98.55 credits for meeting herbaceous wetland vegetation interim success criteria;however, the FDEP inspection report documents that the success criteria is not being met.Furthermore, changes in the permit language appear to correlate the lowering of the L-31E culverts with the success of vegetation planted in graded and restored areas.However, it is not clear how the success of vegetation in areas upstream of the L-31E culverts is related to the lowering of the control elevation for the weirs.b.In addition, specific Condition 20 in the Modification refers to the"Credit release schedule on the next page..."-Yet, the attached credit release schedule has been modified to actually add credits and the"Time Lag&Risk" has been modified from 33.08 to-129.82.It is unclear whether there was an error in the calculation or if there was an actual increase in the allowable credits based on the subject permit modification.
c.The modification document states" This modification releases a total of 98.55 freshwater herbaceous credits to the EMB2.The credits are being released in accordance with Specific Condition 20 and the credit release schedule of Environmental Resources Permit (ERP)#0193232-055." However, the credit release schedule being referenced is actually from the 2013 permit modification and is different than the one that is attached to the current modification.
Specifically, the credit release schedule referenced does not indicate that the credits can be released incrementally.
Page 5 of 5 5.Miami-Dade County DERM Consent Agreement with FPL a.The subject modification conflicts with the October 7, 2015 DERM Consent Agreement in that resolution of paragraph 17.c.i.relating to the control elevation of the culverts has not been achieved.DERM and FPL have not concluded discussions on this matter and any submittals to DERM by FPL to change the culvert settings have not been finalized by both parties.Furthermore, the Consent Agreement requires FPL to take into account its efforts to improve CCS water quality and the potential and actual impacts of such actions on water resources outside the CCS, to not cause or contribute to the exacerbation of alleged violations of County water quality standards or criteria or future violations of County water quality standards or criteria in the groundwater or surface waters outside the CCS.In order to adequately evaluate DEP's action, DERM is respectfully requesting the following records and information:
a)All information/data and analysis that FDEP has relied upon for the modification of the permit and for its determination that these permit modifications"are not expected to result in any adverse environmental impacts or water quality degradation, and will not be contrary to public interest" as stated in FDEP's June 28, 2018 letter approving the permit modifications.
b)All data that FDEP has received from the mitigation bank including, but not limited to, all stage and water quality data from the four monitored culverts, as well as all stage data from all monitoring locations downstream of the L-31 E canal.c)Finally, DERM requests a copy of any notifications the permittee has provided to FDEP pursuant to the requirements of General Condition 10 of the above referenced permit.Please contact me at 305-372-6754 if you have any questions regarding this matter.Sincerely, cee N.Hefty, Director Division of Environmental Resources Management ec: John Truitt, Deputy Secretary Regulatory Programs, Florida Department of Environmental Protection Ernest Marks, Executive Director South Florida Water Management District Michael W.Sole, Vice President, Environmental Services, NextEra Energy Inc.Matthew Raffenberg, Senior Director-Environmental Services, FPL/NextEra Abbie Schwaderer-Raurell, Assistant County Attorney Miami-Dade County Rashid Istambouli, RER Sr.Division Chief Division of Environmental Resources Management Craig Grossenbacher, RER Division Chief Division of Environmental Resources Management Lisa Spadafina, RER Division Chief, Division of Environmental Resources Management Wilbur Mayorga, RER Division Chief.Division of Environmental Resources Management Donna Gordon, RER Section Chief, Division of Environmental Resources Management
SIN 3 l/\l H 0V11V 00.5 11.5 22.5 33.51/1/20007/1/20001/1/20017/1/20011/1/20027/1/20021/1/20037/1/20031/1/20047/1/20041/1/20057/1/20051/1/20067/1/20061/1/20077/1/20071/1/20087/1/20081/1/20097/1/20091/1/20107/1/20101/1/20117/1/20111/1/20127/1/20121/1/20137/1/20131/1/20147/1/20141/1/20157/1/20151/1/20167/1/20161/1/20177/1/20171/1/2018Stage (ft NGVD)
Model Lands Basin L-31E Water Levels 1/1/2000 - 6/30/2018 S-20 Stage (ft NGVD)Sea Level (0.67 ft NGVD)
Prepared in cooperation with Miami-Dade CountyMap of the Approximate Inland Extent of Saltwater at the Base of the Biscayne Aquifer in the Model Land Area of Miami-Dade County, Florida, 2016
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!FKS 9 48 FKS 7 98 FKS 6 51 FKS 5 31 FKS 1 57 G-1180 22 G-3167 65 FKS 2 763 G-3976 36 G-3900 31 G-3166 150 G-1603 643 FKS 4 3,150 FKS 3 7,375 G-3342 2,390 G-1264 8,300 FKS 8 10,050 G-3855 7,960 G-3698 2,830 TPGW-9L 25.2 TPGW-8L 46.2 TPGW-7L 2,750 TPGW-6L 7,570 G-3966S 5,610 G-3946D 5,780 G-3699 10,700 TPGW-5L 12,300 TPGW-4L 15,200 TPGW-3L 28,500 TPGW-2L 31,200 TPGW-1L 29,100 SWIM well 130 TPGW-14L 27,800 TPGW-13L 36,800 TPGW-12L 27,100 TPGW-11L 25,300 TPGW-10L 26,400 ACI-MW-15 2,480 ACI-MW-09 30.8 ACI-MW-05 47.4 ACI-MW-04 48.5 ACI-MW-03 17.8 ACI-MW-16 36.9Florid a Key s Aqueduc t AuthorityLeisure CityFlorid a CityWittkop ParkNewtonRedavoHomestead Airforce BaseNaranja ParkHarri s ParkEverglade s Labor Camp Sec34-MW-02-FS FLORIDA M ia m i-DadeCountyStudy areaEXPLANATION
!Monitoring well name and chloride concentration, in milligrams per literWell field Approximate inland extent of saltwater in 2011 (Prinos and others, 2014)
Approximation Dashed where data are insufficient Approximate inland extent of saltwater in 2016 Approximation Dashed where data are insufficient G-3698 2,830 Model Land ArealanaC 011-CCard Sound Barnes SoundLittle Card Sound Biscayne Bay Cooling canal system A TLANTIC OCEAN 0 2 4 MILES 0 2 4 KILOMETERSScientific Investigations Map 3380U.S. Department of the InteriorU.S. Geological Survey Cover. Map showing the approximate extent of saltwater at the base of the Biscayne aquifer in the Model Land Area of Miami-Dade County, Florida, 2016. See https://doi.org/10.3133/sim3380 for map sheet.
Map of the Approximate Inland Extent of Saltwater at the Base of the Biscayne Aquifer in the Model Land Area of Miami-Dade County, Florida, 2016By Scott T. Prinos Prepared in cooperation with Miami-Dade County Scientific Investigations Map 3380 U.S. Department of the Interior U.S. Geological Survey U.S. Department of the InteriorRYAN K. ZINKE, Secretary U.S. Geological SurveyWilliam H. Werkheise r , Acting Director U.S. Geological Survey, Reston, Virginia: 2 0 1 7For more information on the USGS-the Federal source for science about the Earth, its natural and living resources, natural hazards, and the environment-visit https://www.usgs.gov or call 1-888-ASK-USGS.
For an overview of USGS information products, including maps, imagery , and publications, visit https://store.usgs.gov
.Any use of trade, firm, or product names is for descriptive purposes only and does not imply endorsement by the
U.S. Government.Although this information product, for the most part, is in the public domain, it also may contain copyrighted materials as noted in the text. Permission to reproduce copyrighted items must be secured from the copyright owner.
Suggested citation:Prinos, S.T., 2017, Map of the approximate inland extent of saltwater at the base of the Biscayne aquifer in the Model
Land Area of Miami-Dade County, Florida
- U.S. Geological Survey Scientific Investigations Map 3380, 8-p. pamphlet, 1 sheet, https://doi.org/10.3133/sim3380
.ISSN 2329-132X (online) iiiAcknowledgments The authors would like to acknowledge the organizations that provided data for the study area: EAS Engineering, Inc., Florida Keys Aqueduct Authority, Florida Power & Light Company, Miami-Dade County, and South Florida Water Management District. Without the data provided by these organizations, the map in this report could not have been created.
v Contents Acknowledgments
.......................................................................................................................................
iii Abstract ..........................................................................................................................................................
1 Introduction
....................................................................................................................................................
1 Mapping the Approximate Inland Extent of the Saltwater Interface
...................................................
2 Approximating the Rate of Movement of the Saltwater Interface
.......................................................
2 Monitoring Network Improvements
..........................................................................................................
3 References Cited
...........................................................................................................................................
4 Appendix 1.
Estimation of Chloride Concentrations at Wells Where Conductivity Profiles Were Used for Monitoring
..................................................................................................
5 S heet[Available from https://doi.org/10.3133/sim3380
]1.Map of the approximate inland extent of saltwater at the base of the Biscayneaquifer in the Model Land Area of Miami-Dade County, Florida, 2016Conversion Factors SI to Inch/Pound Multiply ByTo obtain Length meter (m)3.281 foot (ft) kilometer (km) 0.6214 mile (mi)Area square kilometer (km 2)247.1 acre square kilometer (km 2)0.3861 square mile (mi 2)Volume liter (L)0.2642 gallon (gal) liter (L)61.02 cubic inch (in
- 3) Flow rate meter per year (m/yr) 3.281 foot per year (ft/yr)
Mass gram (g)0.03527 ounce, avoirdupois (oz) kilogram (kg) 2.205 pound, avoirdupois (lb)
Electrical conductivity siemens per meter (S/m) 10,000 microsiemens per centimeter vi Electrical conductivity in microsiemens per centimeter [S/cm] can be converted to electrical resistivity in ohm-meters [ohm m] as follows: = 10,000/.Temperature in degrees Celsius (°C) may be converted to degrees Fahrenheit (°F) as follows:
°F = (1.8 x °C) + 32 Datum Horizontal coordinate information is referenced to the North American Datum of 1983 (NAD 83).
Supplemental Information Specific conductance is given in microsiemens per centimeter at 25 degrees Celsius (µS/cm at 25 °C).Concentrations of chemical constituents in water are given in milligrams per liter (mg/L).
Abbreviations bls below land surface GIS geographic information system TSEMIL time-series electromagnetic-induction log (dataset)
USGS U.S. Geological Survey Map of the Approximate Inland Extent of Saltwater at the Base of the Biscayne Aquifer in the Model Land Area of Miami-Dade County, Florida, 2016 By Scott T. PrinosAbstract The inland extent of saltwater at the base of the Biscayne aquifer in the Model Land Area of Miami-Dade County, Florida, was mapped in 2011. Since that time, the saltwater interface has continued to move inland. The
updated approximation of the inland extent of saltwater and
an improved understanding of the rate of movement of the saltwater interface are necessary. A geographic information
system was used to create a map using the data collected by the organizations that monitor water salinity in this area. An
average rate of saltwater interface movement of 140 meters
per year was estimated by dividing the distance between two monitoring wells (TPGW-7L and Sec34-MW-02-FS) by the travel time. The travel time was determined by estimating
the dates of arrival of the saltwater interface at the wells and computing the difference. This estimate assumes that the
interface is traveling east to west between the two monitoring wells. Although monitoring is spatially limited in this area
and some of the wells are not ideally designed for salinity
monitoring, the monitoring network in this area is improving
in spatial distribution and most of the new wells are well designed for salinity monitoring. The approximation of the
inland extent of the saltwater interface and the estimated rate
of movement of the interface are dependent on existing data.
Improved estimates could be obtained by installing uniformly
designed monitoring wells in systematic transects extending
landward of the advancing saltwater interface.Introduction Seawater began intruding the Biscayne aquifer of Miami-Dade County early in the 20th century because of a decline in the fresh groundwater level, estimated to have been 2.9 meters (m)below predrainage conditions near Miami (Prinos and others, 2014). By 2011, approximately 1,200 square kilometers (km
- 2) of the mainland part of the Biscayne aquifer were intruded by saltwater (Prinos and others, 2014). Intrusion
of the Biscayne aquifer by saltwater is a concern because it can render the water unpotable in affected parts of the aquifer.
The maximum concentration of chloride allowed in drinking
Protection Agency, 2014), whereas saltwater-intruded parts of
the aquifer commonly have water with chloride concentrations of 1,000 mg/L or greater.
The inland extent of saltwater at the base of the Biscayne aquifer was last mapped by Prinos and others (2014) in 2011.
Since that time, saltwater has continued to intrude beneath
drained wetland area in southeastern Miami-Dade County that is bordered on the east and south sides by Biscayne Bay, Card Sound, Little Card Sound, and Barnes Sound. A system of
of surface water in this area. There is an extensive system of
cooling canals in the eastern part of this area that has been
hypersaline at times (Hughes and others, 2010).In the Model Land Area, the saltwater interface
approximation of the inland extent of saltwater and an
improved understanding of the rate of movement of the
approximate inland extent of saltwater in the Model Land Area
in 2016 and approximated the average rate of movement of the
saltwater interface in this area based on data collected between 2007 and 2014. This study aligns directly with the strategic
forecasting, and securing freshwater for America's future.
The purpose of this report is to provide a map of the saltwater
interface (2016), an estimate of the rate of interface movement
given the dates of arrival at two wells, and a description of the methodologies used to arrive at these results. The analyses and
estimates are based on available data from existing monitoring wells in the Model Land Area.
2 Map of the Approximate Inland Extent of Saltwater at the Base of the Biscayne Aquifer, Miami-Dade County, Florida, 2016Mapping the Approximate Inland Extent of the Saltwater Interface The approximate inland extent of saltwater in the Biscayne aquifer was determined by using (1) chloride
collected from monitoring wells, (2) water conductivity
collected in polyvinyl-chloride-cased monitoring wells. This
Florida Keys Aqueduct Authority, the Florida Power & Light Company, the South Florida Water Management District
by the SFWMD for this study area had been collected by the other four organizations, so they are mostly redundant. The
information was entered into a geographic information system (GIS) for analysis and mapping. Data used to make the map
are available as a data release (Prinos, 2017).
Sampling, analysis, and quality assurance procedures of the organizations collecting salinity data in the study area vary.
Procedures used by the Florida Power & Light Company for sampling and quality assurance are described in the Turkey Point Quality Assurance Project Plan (Florida Power & Light Company, 2011). These procedures are likely among the most stringent used by organizations collecting salinity data in the study area. This plan was drafted jointly by the Florida
& Light Company, and the SFWMD and was approved by
Branch of Quality Systems Standard Reference Sample Semi-
and the Florida Power & Light Company use laboratories that
Accreditation Program. Participation in this accreditation
without reviewing the results of the accreditation testing for
each laboratory used.
The approximate saltwater interface is represented by the 1,000-mg/L isochlor at the base of the Biscayne aquifer. The
word "approximate" is used because the spatial distribution
precise representation. The accuracy and precision of this
approximation is best evaluated on a location-by-location basis, based on the available monitoring wells. The locations of the monitoring wells and the chloride concentration values
are shown on the map (sheet 1, available at https://doi.
org/10.3133/sim3380
). The line depicting the approximate inland extent of saltwater is dashed where the monitoring well
precise approximation. conductivity provide additional qualitative insights for
water that do not correspond to the open interval of the well
and temporal changes in the depth of the top of the saltwater for monitoring, chloride concentrations were estimated by
using a relation based on a linear regression of the chloride
appendix 1.
The majority of the monitoring wells used for this analysis have short open intervals (about 1.5 meters [m] or
less), but 37 percent have open intervals of 8 to 40 m (Prinos, 2017). The long open-interval wells are not ideal for salinity monitoring for the reasons summarized in Prinos (2013) and
Prinos and V alderrama (2015), but they are the only wells available at some locations.
A p p r o ximating the Rate of Movement o f the Saltwater Interface The saltwater interface in the study area is advancing at an estimated average rate of 140 meters per year (m/yr).
This estimate is based on limited data because there are few
wells in this area where the date of arrival of the saltwater
interface can be ascertained. Most wells were installed either
after the saltwater interface had already passed the location or where the saltwater interface has not yet arrived. The
estimate is based on data from monitoring wells Sec34-
Inc., and the Florida Power & Light Company, respectively.
from well Sec34-MW-02-FS are available in Prinos (2017).
W ell TPGW-7L is open to the aquifer from 24 to 26 m
below land surface (bls), which is near the depth of the base
of the Biscayne aquifer at this location (Fish and Stewart, 1991). The chloride concentration in water samples from well TPGW-7L increased from 180 to 825 mg/L between December 3, 2013, and March 11, 2014, and from 825 to 1,300 mg/L between March 11, 2014, and June 9, 2014.
2 (appendix 1), conductance values measured at this depth
equate to chloride concentrations of about 190, 530, 930, and
2008, and May 15, 2008, respectively.
Monitoring Network Improvements 3 The average rate of saltwater interface movement was estimated by dividing the distance between the wells (830 m) by the difference between the interpolated dates of arrival of chloride concentrations of 250 and 1,000 mg/L at each well. The interpolated dates of arrival at well Sec34-
for concentrations of 250 and 1,000 mg/L, respectively.
The interpolated dates of arrival at well TPGW-7L were December 13, 2013, and April 13, 2014, for concentrations of 250 and 1,000 mg/L, respectively. Given these dates and the
distance between these wells, the estimated rate of movement
of the front is 137 m/yr based on a chloride concentration of 250 mg/L, and the estimated rate based on a concentration of 1,000 mg/L is 138 m/yr. These estimates can be rounded to an average estimate of 140 m/yr. This rate of movement was used to help interpolate the location of the 1,000-mg/L isochlor in the Model Land Area.
This estimate assumes that the direction of front movement is parallel to a line passing through these two well
locations, and that the rate of front movement is constant.
interface elsewhere in the study area assumes that (1) effective
porosity is uniform throughout this area, (2) direction of
front movement is east to west, and (3) that the rate of front movement is the same throughout this area. Additional
monitoring is needed to evaluate these assumptions (see
Given the stated assumptions, the saltwater interface may
future movement may be conservative because withdrawals
travel.Monitoring Network ImprovementsWithin the map, the line depicting the approximation of the inland extent of the saltwater interface is dashed
near the Card Sound Road Canal and in the area around
an accurate delineation of the interface. These areas were
previously mapped by using helicopter electromagnetic
surveys (Fitterman and Prinos, 2012) and time-domain electromagnetic soundings (Fitterman and others, 2011).
Monitoring in these areas currently consists of only a few
wells that are too far from the expected current location of the
interface to provide relevant information. Monitoring near the
edge of the elongated extension of saltwater that had intruded
along the Card Sound Road Canal (Prinos and others, 2014) is
almost nonexistent.
Given the rate of movement of the saltwater interface estimated in this investigation, the chloride concentrations of samples from some of the monitoring wells on the freshwater side of the interface may not exceed 1,000 mg/L for many years. Monitoring well FKS 9, for example, is 0.86 km from the estimated location of the saltwater interface. The 1,000-mg/L isochlor may not arrive at this well until 2023, if the rate of movement of the saltwater interface proceeds at the average rate estimated in this study. Better estimates of
the rates of movement are needed before 2023, particularly
because the rate of movement may not be constant.
Monitoring well FKS 5 is even farther from the approximated location of the saltwater interface than well FKS 9. The rate
and direction of movement of the saltwater interface near well
FKS 5 are unknown. If the rate of movement were the same as that between wells Sec34-MW-02-FS and TPGW-7L, the 1,000-mg/L isochlor may not reach this well for 26 years if
the interface moves northward, or 17 years if the interface moves westward. Water managers would most likely need to
have a better understanding of the location of the saltwater
interface, its rate of movement, and direction of movement
than currently provided near FKS 5.Differences in the design, placement, quality of chemical analyses, and type of monitoring can add uncertainty to this analysis. The analysis of the rate of movement of the saltwater interface between monitoring wells Sec34-MW-02-FS and TPGW-7L, for example, required a number of estimations,
chloride, the relation between pumped water samples and
in situ measurements of conductance, and the conversion of
conversions increase uncertainty. Some monitoring wells, such as well Sec34-MW-02-FS and many of the wells monitored by the Florida Keys Aqueduct Authority, are designed to monitor the depth of the
top of the saltwater interface through the collection of water
Because these wells have long open intervals, the sample
and Valderrama, 2015). Although several organizations base
their sampling on the Standard Operating Procedures of the
(2013) states that these procedures "call for sampling of long
open-interval wells by pumping from near the top of the water
column or top of the open interval, which could result in
samples that are not representative of maximum salinity in the
participates in a quality assurance testing program (see the
Interface section of this report).
be improved by placing monitoring wells along a transect, spaced at distances that would allow timely detection of any
variations in the rate of movement of the saltwater interface, and parallel to the direction of movement of the interface. If
resulting data could be used to evaluate spatial differences in
the rates of movement of the saltwater interface at locations
4 Map of the Approximate Inland Extent of Saltwater at the Base of the Biscayne Aquifer, Miami-Dade County, Florida, 2016 datasets in wells in each transect could provide information on
monitoring methods at wells in each transect could reduce the
uncertainty in the estimated rate of movement.References Cited Geological Survey Water-Resources Investigations Report 90-4108, 50 p., 11 sheets.Fitterman, D.V., Deszcz-Pan, Maria, and Prinos, S.T., 2012, Helicopter electromagnetic survey of the Model Land
Geological Survey Open-File Report 2012-1176, 77 p., 39 pls., accessed January 5, 2017, at https://pubs.usgs.gov/of/2012/1176/
.Fitterman, D.V., and Prinos, S.T., 2011, Results of time-domain electromagnetic soundings in Miami-Dade and
Survey Open File Report 2011-1299, 289 p., accessed
January 5, 2017, at https://pubs.usgs.gov/of/2011/1299/
.
2008, Groundwater sampling: Florida Department of
February 10, 2017, at sop/sops.htm
.Florida Power & Light Company, 2011, Quality Assurance Project Plan-Turkey Point Monitoring Project: Florida Power & Light Company, 170 p., 9 app., accessed February 22, 2017, at https://www.sfwmd.gov/documents-
.
salinization: Hydrogeology Journal, v. 18, p. 25-38.system of the Big Cypress Basin, southwest Florida, and a proposed plan for improved salinity monitoring:
58 p., accessed January 5, 2017, at https://pubs.usgs.gov/
of/2013/1088/
.Prinos, S.T., 2017, Data pertaining to mapping the approximate inland extent of saltwater in the Biscayne aquifer, in the Model Land Area of Miami-Dade County,
http://dx.doi.org/10.5066/F7R78CF8. Prinos, S.T., and Valderrama, Robert, 2015, Changes in the saltwater interface corresponding to the installation
of a seepage barrier near Lake Okeechobee, Florida:
24 p., accessed January 5, 2017, at https://pubs.usgs.gov/
of/2014/1256/
.Prinos, S.T., Wacker, M.A., Cunningham, K.J., and Fitterman, D.V., 2014, Origins and delineation of saltwater intrusion
in the Biscayne aquifer and changes in the distribution of accessed January 5, 2017, at http://dx.doi.org/10.3133/
sir20145025
.drinking water standards: Guidance for nuisance chemicals:
079, accessed January 26, 2011, at http://water.epa.gov/
drink/contaminants/secondarystandards.cfm
.
Survey Techniques of Water-Resources Investigations, book 9, chaps. A1-A9, available online at http://pubs.water.
usgs.gov/twri9A
.
Appendix 1 5 Appendix 1.
Estimation of Chloride Concentrations at Wells Where Conductivity Profiles Were Used for Monitoring used for monitoring, chloride concentrations were estimated by using a relation based on a linear regression of the chloride September 26, 2016, from 178 monitoring sites sampled
The relation is expressed as cc = 0.3458 scwhere cc is the chloride concentration in milligrams per liter, and scper centimeter.
following relation (Carlson, [n.d.]).
sc = c/(1 + r (Twhere c is the actual conductance measured in microsiemens per centimeter, T is the temperature of the sample in degrees Celsius, and r
the sample. conductivity provide additional qualitative insights for
water that do not correspond to the open interval of the well
and temporal changes in the depth of the top of the saltwater
interface.
The majority of the monitoring wells used for this analysis have short open intervals (about 1.5 meters [m] or less), but 37 percent have open intervals of 8 to 40 m (Prinos, 2017). The long open-interval wells are not ideal for salinity
monitoring for the reasons summarized in Prinos (2013) and Prinos and Valderrama (2015), but they are the only wells
available at some locations. References Cited accessed March 6, 2017, at https://in-situ.com/wp-content/
.system of the Big Cypress Basin, southwest Florida, and a proposed plan for improved salinity monitoring:
58 p., accessed January 5, 2017, at https://pubs.usgs.gov/
of/2013/1088/
.Prinos, S.T., 2017, Data pertaining to mapping the approximate inland extent of saltwater in the Biscayne aquifer, in the Model Land Area of Miami-Dade County,
http://dx.doi.org/10.5066/F7R78CF8. Prinos, S.T., and Valderrama, Robert, 2015, Changes in the saltwater interface corresponding to the installation
of a seepage barrier near Lake Okeechobee, Florida:
24 p., accessed January 5, 2017, at https://pubs.usgs.gov/
of/2014/1256/
.System-Web interface, accessed September 28, 2016, at
.Appendix 1 6 Map of the Approximate Inland Extent of Saltwater at the Base of the Biscayne Aquifer, Miami-Dade County, Florida, 2016Table 1-1.
Listing of U.S. Geological Survey monitoring sites in southern Florida from which water samples were collected to evaluate specific conductance and chloride concentration.
USGS station identifier Site name 262313080044401 PB -1457 262209080044702 PB -1669261100080140401 G -1212261122080083401 G -1232 260547080105801 G -2352 260920080092201 G -2898260551080111901 G -2957 261740080054101 G -2893 255916080090401 G -1435 255910080085802 G -2294 255919080091202 G -2409 255919080091203 G -2410 255936080091701 G -2477 255936080091702 G -2478 255916080092001 G -2965 260037080100700 Hollywood Canal at Hollywood Blvd, Hollywood, FL 260104080101300 Hollywood Canal at Johnson St, Hollywood, FL 260225080095800FL260212080112500FL 260132080094900Hollywood Canal at Taft St, Hollywood, FL 260041080093101 G -2425 260041080093102 G -2426 260120080093401 G -2441 260155080092002 G -2612 260026080095801 G -2956 254943080121501 F - 45 254841080164401 G - 571 255350080105801 G - 894 254107080165201 G - 896 254201080173001 G - 901 254106080174601 G -1009B 252947080235301G -1180 254813080161501 G -1351 254833080155801 G -1354 255222080123001 G -3224 254457080160301 G -3229 254946080172601 G -3250 252714080260901 G-3976 USGS station identifier Site name255453080110801 G-3978 254601080150301 G-3977 254156080172101 G -3607 252814080244101 G -3698 252652080244301 G -3699 252650080252701 G -3855 253253080221201 G -3885 253527080195401 G -3886 253924080174601 G -3887A 253924080174602 G -3887B 254542080145901 G -3888A 254542080145902 G -3888B 254542080145903 G -3888C 253948080250701 G -3897 254152080282601 G -3898 253419080223701 G -3899 252718080264901 G -3900 252506080300601 G -3901 252431080261001 G -3946D 252431080261002 G -3946S255011080124501 G -3947 255515080103601 G -3948D 255515080103602 G -3948S 255733080195601 G -3949D 255733080195602 G -3949I 255733080195603 G -3949S 254824080155301 G -3964 254500080162801 G -3965 252719080253601 G -3966D 252719080253602 G -3966S 253335080213501 G -3967255315080111501 F - 279 254828080161501 G - 354 254335080170501 G - 432 254855080163701 G - 548 253652080183701 G - 939 253202080232601 G -3162 253831080180204 G -3313C 253831080180206255358080114101 G -3601255116080120601 G -3602 Appendix 1 7Table 1-1.
Listing of U.S. Geological Survey monitoring sites in southern Florida from which water samples were collected to evaluate specific conductance and chloride concentration.-Continued USGS station identifier Site name 254908080125201 G -3603 254722080152201 G -3604 254629080143101 G -3605 254341080174001 G -3606 254108080170601 G -3608 254005080171601 G -3609 253819080183201 G -3610 253710080184701G -3611 253457080195501 G -3612 253024080231001 G -3615 253027080234701 G -3700 253214080224601 G -3701 253334080213601 G -3702 254822080125501 G -3704 255625080094901 G -3705 261302081473901 C - 489261156081475801 C - 516 261002081483701 C - 525 261018081484101 C - 526 261200081483001 C - 528 260549081441901 C - 600 261802081354801 C - 688 261347081351201 C - 953 261620081464402 C -1004R 261604081480901 C -1059261311081480101 C -1061 260137081375901 C -1063 262228081361902 C -1080 261403080070801 G -2149260342080115902 G -2264 261446080062801 G -2445 261724080054603 G -2693260242080101101 G -2697 261643080055901 G -2752 261740080054101 G -2893 261304080072501 G -2896 261030080083301 G -2897 260804080092701 G -2899260325080113901 G -2900 260638080104801 G -2902 255843080090901 G -2903 USGS station identifier Site name260534080110801 G -2904 262839081503100L - 735 262022081464201L - 738 263532081592202L -1136 263813081552801L -2640 263819081585801L -2701 263955082083102L -2820263117082051002L -2821 264053081572501L -4820 262513081472002L -5668R 261926081454702L -5745R 264123080053801 PB - 809 263044080035102PB -1195 262755080040101 PB -1707262803080041101 PB -1714 263453080031501 PB -1717 263633080031401 PB -1723 265550080070701 PB -1732265611080080201 PB -1733 265006081042502GL - 334I 265006081042501GL - 334S 265006081042503GL - 334D 264912081024602GL -332S 264912081024601GL -332 264843080591502GL - 333I 264843080591501GL - 333S 264843080591503GL - 333D 264532080545902264532080545901264343080511601 PB -1843S264343080511602 PB -1843I264343080511603 PB -1843D 264154080480302 PB -1822S 264154080480301 PB -1822 264050080435502 PB -1842I 264050080435501 PB -1842S 264050080435503 PB -1842D 264814080414302 PB -1819S 264814080414301 PB -1819 264926080394503 PB -1848D 264930080394703 PB -1847D 8 Map of the Approximate Inland Extent of Saltwater at the Base of the Biscayne Aquifer, Miami-Dade County , Florida, 2016Table 1-1. Listing of U.S. Geological Survey monitoring sites in southern Florida from which water samples were collected to evaluate specific conductance and chloride concentration.-Continued USGS station identifier Site name265138080375802PB -1818S265138080375801PB -1818 265142080374202PB -1817S 265142080374201PB -1817 265208080373902PB -1845I 265208080373901PB -1845S 265208080373903PB -1845D 265200080373101PB -1846S 265428080364502PB -1816S USGS station identifier Site name265428080364501PB -1816 265519080364902PB -1815S 265519080364901PB -1815 265701080363103PB -1844D 265701080363102PB -1844I 265701080363101PB -1844S 265839080365202M -1369I 265839080365201M -1369D For more information about this publication, contact:Director, Caribbean-Florida Water Science Center U.S. Geological Survey
4446 Pet Lane, Suite 108
Lutz, FL 33559
(813) 498-5000Or visit the USGS Caribbean-Florida Water Science Center website at:
https://fl.water.usgs.gov Publishing support provided by
Lafayette Publishing Service Center
Prinos-Map of the Approximate Inland Extent of Saltwater at the Base of the Biscayne Aquifer, Miami-Dade County, Florida, 2016
-SIM 3380 ISSN 2329-132X (online) https://doi.org/10.3133/sim3380 FLORIDA KEYS AQUADUCT AUTHORITYFLORIDA CITYWITTKOP PARKNEWTONHARRIS PARKEVERGLADES LABOR CAMPSaltline_trends_20180430.mxd - GMB - May 7, 2018 Salt Intrusion at the Base of the Biscayne Aquifer (1,000 mg/L chlorides) US Geological Survey Data 2016 Salt Intrusion Line2011 Salt Intrusion Line1995 Salt Intrusion Line Wellfield Protection AreasMiami-Dade CountySalt Intrusion Extent 0 1 2 3 4 5 60.5MilesFlorida City CanalCard Sound Road borrow canalDistance fromCoast: 10.6 milesDistance fromCoast: 6.5 miles 020004000 6000 800010000 12000 14000 16000 18000mg/LDERMClassIPermitRequiredMonitoringinL31ECanalJune2015toMay29,2018SummaryofChlorideResultsTPSWC 1BTPSWC 2BTPSWC 3BMDCChapter24Standard(500mg/L,wasteshallnotincreasenaturalbackgroundmorethan10percent)
I-2I-1I-4I-3EEL2EEL1L31E-FL31E-CL31E-BL31E-EL31E-DL31E-A.Specific Conductance Sampling PointsCanalsMiami-Dade EEL ProgramSFWMDFlorida Power and LightRockmining Lands and Associated MitigationState of FloridaFederalPrivateRockmining Lands and Associated MitigationFlorida Power and LightRockmining Lands and Associated MitigationModel Lands Surface Water Specific ConductanceL-31E borrow canal and Model Lands South canal April 2018DepthSpCond (u/s)T (0.41 m)9100.7M (1.45m)9097.6B (3.477m)9793L31E-ADepthSpCond (u/s)T (0.25 m)4835.1M (1.021m)9146.1B (2.176m)8642L31E-BDepthSpCond (u/s)T (0.22 m)9224.6M (1.087m)9245.4B (2.117m)8669.7I-1DepthSpCond (u/s)T (0.49 m)9336.1M (1.7m)9325.9B (2.499m)9130.6I-2DepthSpCond (u/s)T (0.132m)9462.3M (1.549m)9460.6B (2.951m)9322.3L31E-CDepthSpCond (u/s)T (0.24m)21744.3M (0.891m)21588.7B (1.841m)21612.6L31E-DDepthSpCond (u/s)T (0.071m)21529.3M (1.493m)21528.6B (2.932m)45473I-3DepthSpCond (u/s)T (0.079m)21347 M (0.956m)21377.1B (1.956m)22714.6L31E-EDepthSpCond (u/s)T (0.299m)21580 M (0.939m)21534.6B (2.077m)23692.6I-4DepthSpCond (u/s)T (0.179m)21444.5 M (0.707m)21424.5B (1.653m)31860.2L31E-FDepthSpCond (u/s)T (0.179m)5934.9EEL2DepthSpCond (u/s)T (0.1m)5408EEL1 01.5 34.5 60.75Miles Model Lands Hydrology and FPL Everglades Mitigation Bank L-31E Culvert Weir Operation RER-DERM Water Resources Coordination and Education Division February 15, 2018
Model Lands Hydrology Isolated by Roads/Levees No Connection to Regional Canal System Rain-driven Palm Drive culverts (restoration)
S-20 Everglades Mitigation Bank L-31E culvert weirs Interceptor Ditch pumps Model Lands Hydrology S-20 Interceptor Ditch pumps Model Lands Hydrology and S-20 Operations Central and Southern Florida Project for Flood Control and Other Purposes Master Water Control Manual - East Coast Canals - Volume 5 Model Lands Hydrology and S-20 Operations C&SF Project Structure Manual, S
-20 Section (revised 1/16/2003):
Water Elevation (ft NGVD) Model Lands Groundwater Control Elevations Current Water Management 0.5 ft 1.0 ft 1.5 ft 2.0 ft 2.5 ft 3.0 ft 3.5 ft Mean Sea Level FPL Everglades Mitigation Bank L-31E Culvert Weir Operations Existing S-20 Operations for Flood Control, Salt Intrusion Control FPL-EMB culvert operations, per Special Condition 15(d) of FDEP Permit 0193232-001, Mod 055 (June 25, 2013): *"Preliminarily, during the wet season (May - September), the L-31-E control structures shall be set at an elevation that is at least 0.2 feet lower than the water level invert setting of the S-20 structure. *During the dry season (October - April), they will be set at 0.1 feet lower than the S-20 control elevation setting." Local Wetland Ground Elevation (1.8 ft NGVD at TPGW
-4, close to both S
-20 and EMB culverts)
Water Levels that Support Environmental Services Optimum S-20 Headwater Elevation (per C&SF Master Manual)
31-Aug-1030-Sep-1031-Oct-1030-Nov-1031-Dec-1031-Jan-1128-Feb-1131-Mar-1130-Apr-1131-May-1130-Jun-1131-Jul-1131-Aug-1130-Sep-1131-Oct-1130-Nov-1131-Dec-1131-Jan-1229-Feb-1231-Mar-1230-Apr-1231-May-1230-Jun-1231-Jul-1231-Aug-1230-Sep-1231-Oct-1230-Nov-1231-Dec-1231-Jan-1328-Feb-1331-Mar-1330-Apr-1331-May-1330-Jun-1331-Jul-1331-Aug-1330-Sep-1331-Oct-1330-Nov-1331-Dec-1331-Jan-1428-Feb-1431-Mar-1430-Apr-1431-May-1430-Jun-1431-Jul-1431-Aug-1430-Sep-1431-Oct-1430-Nov-1431-Dec-1431-Jan-15TPGW-4S, August 31, 2010 - February 2, 2015 Water Level (ft NGVD29)Nearby Wetland Ground Elevation (1.8 ft NGVD)Water Elevation (ft NGVD) Model Lands Groundwater Stages Existing Conditions vs. Healthy Ecology 0.5 ft 1.0 ft 1.5 ft 2.0 ft 2.5 ft 3.0 ft Existing S-20 Operations FPL L-31E Culvert Weir Operations Mean Sea Level 3.5 ft 2011: <5 months 2012: <8 months 2013: <4 months 2014: <5 months Healthy Sawgrass Prairie:
8-10 months Hydroperiod
- #Wetzel 2001. Plant Community Parameter Estimates and Documentation for the Across Trophic Level System Simulation (ATLSS). Data Report Prepared for the ATLSS Project Team , University of Tennessee
-Knoxville, 59Pp.
C-111 Spreader Canal Western CERP Project February 2012 - Project Construction completed under SFWMD state
-expedited program June 10, 2014 Congressional Authorization (WRDA 2014) Features: Frog Pond Detention Area Aerojet Canal Features Plugs in C
-11 0 Operational Changes at S
-18C Plug at S-20A Operational Changes at S
-20 Water Elevation (ft NGVD) Model Lands Groundwater Control Elevations CERP Restoration Vision vs. Current Water Management 0.5 ft 1.0 ft 1.5 ft 2.0 ft 2.5 ft 3.0 ft 3.5 ft Mean Sea Level FPL Everglades Mitigation Bank L
-31E Culvert Weir Operations Existing S-20 Operations CERP Restoration Vision CERP Restoration, per C-111 Spreader Canal Western Project FEIS and BBCW Alt O Conceptual Design, Army Corps of Engineers):
- S-20 open and close triggers to be increased 0.5 foot *4 pump stations on Florida City Canal pump up to 150 cfs into the Model Lands Local Wetland Ground Elevation C-111 Spreader Canal Western CERP Project Page xii: OUR CONCLUSION: HYDROPERIOD RESTORATION IS DEPENDENT ON A REDUCTION IN OVERDRAINAGE CAUSED BY CANAL INFRASTRUCTURE
C-111 Spreader Canal Western CERP Project
C-111 Spreader Canal Western CERP Project
C-111 Spreader Canal Western CERP Project Army Corps Permit for construction of the FPL Everglades Mitigation Bank:
FPL L-31E Culvert Elevations Gate elevations were raised from 1.8 to 2.2 ft NGVD per DERM Consent Agreement (Condition 17(c)(i):
Raise control elevations in the Everglades Mitigation Bank. Within 30 days of the effective date of this Consent Agreement, FPL shall raise the control elevations of the FPL Everglades Mitigation Bank ("EMB") culvert weirs to no lower than 0.2 feet lower than the 2.4 foot trigger of the S-20 structure and shall maintain this elevation. After the first year of operation, FPL shall evaluate the change .
in control elevation, in regards to improvements in salinity, water quality, and lift in the area, and if FPL determines that the change in control elevations is not effective, or that FPL is negatively impacted in receiving mitigation credits as a result of this action, FPL will consult with DERM and propose potential alternatives.
FPL EMB L-31E Culvert Elevations FPL Annual Monitoring Report, Everglades Mitigation Bank Phase II (January 2018)
00.5 11.5 22.5 33.5 49/1/201011/1/20101/1/20113/1/20115/1/2011 7/1/20119/1/201111/1/20111/1/20123/1/20125/1/2012 7/1/20129/1/201211/1/20121/1/20133/1/20135/1/2013 7/1/20139/1/201311/1/20131/1/20143/1/20145/1/2014 7/1/20149/1/201411/1/20141/1/20153/1/20155/1/2015 7/1/20159/1/201511/1/20151/1/20163/1/20165/1/2016 7/1/20169/1/201611/1/20161/1/20173/1/20175/1/2017 7/1/20179/1/2017Stage (ft NGVD)
September 1, 2010 to September 30, 2017 FPL- EMB Culverts raised from 1.8 ft NGVD to 2.2 ft NGVD per CA requirement , 10/22/2015 through 4/30/2017 (information provided by FPL)
FPL Everglades Mitigation Bank (EMB)
Culvert Elevations and Water Levels in L
-31 E Canal
0 200 400 600 8001000 1200 1400201120122013201420152016Volume Pumped (MG)
L-31E culvert gates were raised to 2.2 ft NGVD on October 22, 2015 and remained at 2.2 ft NGVD through April 30, 2017 Interceptor Ditch Estimated Dry Season Volume Pumped 2011 - 2016 (January through May)
00.5 1
1.5 2
2.5 30.05.010.0 15.0 20.0 25.0 30.0 35.0 40.01/1/20171/8/20171/15/2017 1/22/2017 1/29/20172/5/20172/12/2017 2/19/2017 2/26/20173/5/20173/12/2017 3/19/2017 3/26/20174/2/2017 4/9/20174/16/2017 4/23/2017 4/30/20175/7/20175/14/2017 5/21/2017 5/28/20176/4/20176/11/2017 6/18/2017 6/25/20177/2/2017 7/9/20177/16/2017 7/23/2017 7/30/20178/6/20178/13/2017 8/20/2017 8/27/20179/3/2017Volume (MG)
Stage (ft NGVD)
ID Daily Pumping Volume (MG)FPL- EMB Culverts raised from 1.8 ft NGVD to 2.2 ft NGVD per CA requirement , 10/22/2015 through 4/30/2017 (information provided by FPL)
L-31E Stage vs. Interceptor Ditch Pumping January 1, 2017 to September 4, 2017
00.3 0.6 0.9 1.2 1.5 1.8 2.1 2.40.05.010.0 15.0 20.0 25.0 30.0 35.0 40.01/1/20171/8/20171/15/2017 1/22/2017 1/29/20172/5/20172/12/2017 2/19/2017 2/26/20173/5/20173/12/2017 3/19/2017 3/26/20174/2/2017 4/9/20174/16/2017 4/23/2017 4/30/20175/7/20175/14/2017 5/21/2017 5/28/20176/4/20176/11/2017 6/18/2017 6/25/20177/2/2017 7/9/20177/16/2017 7/23/2017 7/30/20178/6/20178/13/2017 8/20/2017 8/27/20179/3/2017Stage (ft NGVD) 05,00010,00015,000 20,000 25,000 30,000 35,000 40,0001/1/20171/11/20171/21/2017 1/31/2017 2/10/2017 2/20/20173/2/20173/12/2017 3/22/20174/1/20174/11/2017 4/21/20175/1/20175/11/2017 5/21/2017 5/31/2017 6/10/2017 6/20/2017 6/30/2017 7/10/2017 7/20/2017 7/30/20178/9/20178/19/2017 8/29/2017Specific Conductance
(µS/cm) TPSWC-1B Avg. Daily Sp. Cond. (uS/cm)TPSWC-2B Avg. Daily Sp. Cond. (uS/cm)TPSWC-3B Avg. Daily Sp. Cond. (uS/cm)L-31E Canal Bottom Specific Conductance vs. Surface Water Stage January 1 to September 4, 2017 S-20 Avg. Daily Stage (ft NGVD)
L-31E Canal Uprate and Class I Permit Required Surface Water Monitoring Stations
0.002,000.004,000.00 6,000.00 8,000.0010,000.00 12,000.00 14,000.00 16,000.00May 31 & Jun 1, 2015Jun 15 & 16, 2015Jun 29 & 30, 2015Jul 13 & 14, 2015Jul 27 & 28, 2015August 10 & 11Aug 24 & 25, 2015Sept 8 & 9 2015Sept 21 & 22 2015Oct 5 to 7, 2015Oct 19 & 20, 2015Nov 2 & 4, 2015Nov 16 to 19, 2015Nov 30 to Dec3, 2015Dec 14 & 15, 2015Dec 28 & 29, 2015Jan 11 & 12, 2016Jan 25 & 26, 2016Feb 8 & 9, 2016Feb 22 & 23, 2016Mar 7 & 8, 2016Mar 21 & 22, 2016April 4 & 5, 2016April 18 & 19, 2016May 2 & 3, 2016May 16 & 17, 2016May 31 to Jun 3, 2016Jun 13 & 14, 2016Jun 27 & 28, 2016Jul 11 & 12, 2016Jul 25 & 26, 2016Aug 8 & 9, 2016Aug 22 & 23, 2016Sep 6 & 7, 2016Sept. 19 & 20, 2016Oct. 3 & 4, 2016Oct. 17 & 18, 2016Oct. 31 & Nov 1, 2016Nov 14 & 15, 2016Nov 28 & 29, 2016Dec 12 & 13, 2016Dec 27 & 28, 2016Jan 9 & 10, 2017Jan 23 & 24, 2017Feb 6 & 7, 2017Feb 20 & 21, 2017Mar 6 & 7, 2017Mar 20 & 21, 2017Apr 3 & 4, 2017Apr 24 & 25, 2017May 8 & 9, 2017May22 & 23, 2017June 5 to 7, 2017June 19 & 20, 2017Jul 5 to 8, 2017Jul 17 & 18, 2017Jul 31 & Aug 1, 2017Aug 14 & 15, 2017Aug 28 & 29, 2017Sep 26 to 28, 20179-Oct-17Oct 23 & 24, 2017Nov 6 & 7, 2017Nov 21 & 22, 2017Dec 4 & 5, 2017Dec 18 & 19, 2017Jan 2 & 3, 2018Jan 16 & 17, 2018mg/L TPSWC-1BTPSWC-2BTPSWC-3BMDC Chapter 24 Standard (500 mg/L, waste shall not increase natural background more than 10 percent)DERM Class I Permit Required Monitoring in L
-31E Canal Summary of Chloride Results June 2015 to January 17, 2018
L-31E Canal May 12, 2017 Physical Parameter Surface Water Quality Survey Monitoring sites (20 sites)
3.65 3.65 19.21 4.37 10.65 23.41 0.005.0010.00 15.00 20.00 25.000 to 1 ft.1.01 to 7.99 ft.8 to 9.25 ft.Salinity (PSU)
Depth Below Surface (ft.)
MinMaxL-31E Canal Water Column Physical Parameter Survey Salinity Result Summary, May 12, 2017
0.020.040.0 60.0 80.0100.0 120.0 140.0 160.0 180.0 200.0Jun/Jul 2010Sep-10Dec-10Mar-11Jun-11Sep-11Dec-11Mar-12Jun-12Sep-12Dec-12Mar-13Jun-13Sep-13Dec-13Mar-14Jun-14Sep-14Dec-14Mar-15Jun-15Sep-15Dec-15Mar-16pCi/L TPSWC-1BTPSWC-1TTPSWC-2BTPSWC-2TTPSWC-3BTPSWC-3TL-31E Canal Uprate Monitoring Tritium Results TPSWC-1B, TPSWC-1T, TPSWC-2B, TPSWC-2T, TPSWC-3B & TPSWC
-3T L-31E Canal Uprate Monitoring Tritium Result Summary L-31E Canal Top vs. Bottom (N = 84 for each level) 8 182 60.1 10.3 154 57.2 02040 60 80100 120 140 160 180 200MinMaxAveragepCi/L Top (1 ft. below water surface)Bottom (1 ft. above canal bottom)Agencies screening level threshold (20 pCi/L)
Model Lands Hydrology and FPL Culvert Operations Summary Per CERP, the Model Lands Basin is overdrained by the L-31 E and S-20 water control structure, with water levels occasionally dropping below sea level Overdrainage needs to be stopped to restore both wetland stage and hydroperiod per CERP The amount of drainage from the L
-31 Canal is established by the elevation of the water in the L
-31 E Canal. The water in the L
-31 E canal is drained through FPL's culverts to the stage established by these adjustable culvert weirs when the S
-20 structure is closed.
FPL's preferred setting for L
-31 E canal water level at 1.8 ft NGVD is 1.1 feet lower than the planned CERP open trigger setting and 0.6 feet lower than the planned close trigger.
EMB culvert weir settings at 2.2 ft NGVD reduces overdrainage of the basin CERP authorizes a change in S-20 operations to increase trigger stages by 0.5 ft in order to reduce overdrainage in the Model Lands The S-20 operations change has agency support at local, state, and federal levels The S-20 operations change is expected to make additional water available for release through the FPL culverts
- a "win-win" for all parties
0 5 10 15 20 25 30Salinity(PSU)L31ECanalAverageDailySalinityattheBottomAugust30,2010toJuly16,2018TPSWC 1BAvgDailySalinity(PSU)TPSWC 2BAvgDailySalinity(PSU)TPSWC 3BAvgDailySalinity(PSU) 0 5 10 15 20 25 30 PSU L 31ECanalAverageDailySalinityProfilesJanuary1toJuly16,2018TPSWC 1TAvgDailySalinity(PSU)TPSWC 1BAvgDailySalinity(PSU)TPSWC 2TAvgDailySalinity(PSU)TPSWC 2BAvgDailySalinity(PSU)TPSWC 3TAvgDailySalinity(PSU)TPSWC 3BAvgDailySalinity(PSU)
Water Elevation (ft NGVD) Model Lands Groundwater Control Elevations Current Water Management 0.5 ft 1.0 ft 1.5 ft 2.0 ft 2.5 ft 3.0 ft 3.5 ft Mean Sea Level FPL Everglades Mitigation Bank L-31E Culvert Weir Operations Existing S-20 Operations for Flood Control, Salt Intrusion Control FPL-EMB culvert operations, per Special Condition 15(d) of FDEP Permit 0193232-001, Mod 055 (June 25, 2013): *"Preliminarily, during the wet season (May - September), the L-31-E control structures shall be set at an elevation that is at least 0.2 feet lower than the water level invert setting of the S-20 structure. *During the dry season (October - April), they will be set at 0.1 feet lower than the S-20 control elevation setting." Local Wetland Ground Elevation (1.8 ft NGVD at TPGW
-4, close to both S
-20 and EMB culverts)
Water Levels that Support Environmental Services Optimum S-20 Headwater Elevation (per C&SF Master Manual)
31-Aug-1030-Sep-1031-Oct-1030-Nov-1031-Dec-1031-Jan-1128-Feb-1131-Mar-1130-Apr-1131-May-1130-Jun-1131-Jul-1131-Aug-1130-Sep-1131-Oct-1130-Nov-1131-Dec-1131-Jan-1229-Feb-1231-Mar-1230-Apr-1231-May-1230-Jun-1231-Jul-1231-Aug-1230-Sep-1231-Oct-1230-Nov-1231-Dec-1231-Jan-1328-Feb-1331-Mar-1330-Apr-1331-May-1330-Jun-1331-Jul-1331-Aug-1330-Sep-1331-Oct-1330-Nov-1331-Dec-1331-Jan-1428-Feb-1431-Mar-1430-Apr-1431-May-1430-Jun-1431-Jul-1431-Aug-1430-Sep-1431-Oct-1430-Nov-1431-Dec-1431-Jan-15TPGW-4S, August 31, 2010 - February 2, 2015 Water Level (ft NGVD29)Nearby Wetland Ground Elevation (1.8 ft NGVD)Water Elevation (ft NGVD) Model Lands Groundwater Stages Existing Conditions vs. Healthy Ecology 0.5 ft 1.0 ft 1.5 ft 2.0 ft 2.5 ft 3.0 ft Existing S-20 Operations FPL L-31E Culvert Weir Operations Mean Sea Level 3.5 ft 2011: <5 months 2012: <8 months 2013: <4 months 2014: <5 months Healthy Sawgrass Prairie:
8-10 months Hydroperiod
- #Wetzel 2001. Plant Community Parameter Estimates and Documentation for the Across Trophic Level System Simulation (ATLSS). Data Report Prepared for the ATLSS Project Team , University of Tennessee
-Knoxville, 59Pp.
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