RBG-31212, NPDES Noncompliance Notification:On 890630,duplicative Samples of Effluent from Outfall 005 Yielded Average Total Residual Chlorine of 5.9 mg/1,in Violation of Permitted Max of 2.0 mg/1.Caused by Improper Balance of Hypochlorite

NPDES Noncompliance Notification:On 890630,duplicative Samples of Effluent from Outfall 005 Yielded Average Total Residual Chlorine of 5.9 mg/1,in Violation of Permitted Max of 2.0 mg/1.Caused by Improper Balance of Hypochlorite

ML20246E952
Person / Time
Site:	River Bend
Issue date:	07/05/1989
From:	Deddens J GULF STATES UTILITIES CO.
To:	Oneill M LOUISIANA, STATE OF
References
RBG-31212, NUDOCS 8907130064
Download: ML20246E952 (2)

Text

.- - - - -

[; ,.y-

. C 5

($

GULF STATES UTELITIES COMPANY 'g wm wus . < .

n . .

July 5, 1989 RBG- 31212 File Nos. G1.11.2 Ms. Maureen O'Neill, Assistant Secretary l

Office of Water Resources i Louisiana Department'of Environmental Quality Post Office Box 44091, Capitol Station Baton Rouge, LA 70804-4091 ,

Dear Ms. O'Neill:

Water Discharge Permit No. WP0409 River Bend Station - Unit 1 On Friday, June 30, 1989 at 4:12 p.m. a telephone notification.was called into the Louisiana Department of Environmental Quality (DEQ) concerning a violation of the maximum limitation for total residual chlorine (TRC) at Outfall 005 of: Water Discharge Permit No. WP0409, A follow-up report. is-being provided with further details and corrective action regarding the event.

Outfall 005 is " treated sanitary waste from training center to Grants Bayou". Duplicate samples of this effluent, collected at 1:40 p.m. on June i 30,1989,' yielded an average TRC concentration of 5.9 mg/l which is in

. violation of the perm?tted maximum of 2.0 mg/1. The discharge was stopped immediately upon recognition of the condition (at about 2:00 p.m.).

Discharge flow over the weir crest at the time had been about one gallon per minute (gpm). The normally intermittent receiving stream (West Fork of Grants Bayou) was flowing at about 2,000 gpm at the time due to recent rains; thus, it is unlikely that this chlorine excursion had any significant adverse impact due to the dilution factor. The stream was investigated, immediately downstream of the outfall and at the next readily accessible point (0.3 miles downstream), and no evidence o# damage was found.

The cause of this excursion was an improper balance of hypochlorite tablet dosage and flows. Due to the recent rainfall associated with Tropical l Depression Allison - the facultative/ anaerobic polishing pond had been draining at the maximum capacity of the contact chamber for two days and up until mid-morning on June 30, 1989. Maintenance of the greatest pcssible number of hypochlorite tablets was required to achieve the required minimum of 0.8 mg/l TRC. The pond level reached that of the weir crest and flows abruptly subsided from several gpm to the 1 gpm noted above. A reduction in flow occurred sooner than the operator could react.

l_

gM 89071soo64 spo70s I i \

[DR ADOCM 05o00458 PDC

l,

., .e 4

~

,O'Neill Page 2 GSU plans to upgrade the capacity of the diversion ditches in the near-term, as practicable. Prevention of excursions is sensitive to the

-existing equipment and additional heavy rainfall given the narrow range requirements of 0.8 to 2.0 mg/l TRC. The entire treatment system at Outfall 005 was the subject of a recent evaluation by consulting engineers.

Results and recommendations of this study are being assessed by upper management to determine the best long-term solution.

I- certify under penalty of law that this document and all attachments were prepared under my direction or supervision in accordance with a system designed to assure that qualified personnel properly gather and evaluate the information' submitted. Based on my inquiry of the person or persons who manage the system, or those persons directly responsible for gathering the information submitted, the information submitted is, to the best of my knowledge and belief, true, accurate and wmplete. I am aware that there l are -significant penalties for submitting false information, including the possibility of fine and imprisonment for knowing violations.

Sincerely, geo-J. C. Deddens Senior Vice President JCD/ E /L J C/ch cc: Mr. Myron Knudson, P.E.

Director, Water Management Division (6W)

U. S. Environmental Protection Agency Allied Bank Tower at Fountain Place 1445 Ross Avenue Dallas, TX 75202-2733 Capitol Regional Office Water Pollution Control Division 11720 Airline Highway l

Baton Rouge, LA 70817-1720 l

l U. S. Nuclear Regulatory Commission Document Control Desk i Washington, D.C. 20555 U. S. Nuclear Regulatory Commission i 611 Ryan Plaza Drive, Suite 1000 l Arlington, TX 76011 l

l NRC Resident Inspector Post Office Box 1051 St. Francisville, LA 70775 L__--_-____------._--------___