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Home My WebLink AboutNC0039586_Comments on Draft Permit_19871029o q' OCT 0- 1987 CP&L Carolina Power & Light Company Shearon Harris Energy & Environmental Center Route 1, Box 327 New Hill, North Carolina 27562 PEtiTOFFs & ENG1;NrL-:EH111:G OCT 2 9 1987 Dr. George Everett, Chief Water Quality Section N.C. Division of Environmental Management P.O. Box 27687 Raleigh, NC 27611-7687 RE: Shearon Harris Nuclear Power Plant NPDES Permit NCO039586 Comments on Draft Permit Dear Dr. Everett: , P--. I1114rpt. 041 Serial No.: ESS -87-1307 Carolina Power & Light Company (CP&L) has reviewed the subject draft permit that was received on October 2, 1987. In the public notice published on September 30, 1987, the Division of Environmental Management (DEM) required written comments to be submitted by October 30, 1987. Representatives of CP&L met with Messrs. Arthur Mouberry, Steve Tedder, and others of your staff on October 23, 1987, and discussed CP&L's comments and concerns. A written summary of CP&L's comments are enclosed for your consideration. Also enclosed is a marked -up copy of the draft permit, revised to reflect the changes requested in our,comments. The time spent by your staff in meeting with us and considering our comments is greatly appreciated. If you have any questions or require further information, please contact Mr. Cam Wheeler at 836-6725 in our General Office. Yours very truly, G. H. Warriner Manager Environmental Services CCW/dsm .(4209CCW) Enclosures / cc: Mr. A. Mouberry V Mr. R. W. Van Tilburg ,.0, Enclosure to ESS -87-1307 Carolina Power & Light Company Comments on NPDES Draft Permit NC0039586 For the Shearon Harris Nuclear Power Plant October, 1987 Outfall 001- Cooling Tower Blowdown 1. The first listing of priority pollutants in the table with other effluent characteristic limits and monitoring requirements needs to be clearly referenced to 40 CFR 423. These priority pollutants, as referenced in the Steam Electric Generating Plant Effluent Guidelines (40 CFR 423), need to be monitored only when added by the permittee, and therefore CP&L requests that this item reference footnote "**". 2. The priority pollutants monitoring required in Part III, Condition G, is a different requirement than that discussed above and should be listed separately on this page, referring to an annual composite sample. It could also be made clear that the sample location for such monitoring is downstream of mixing of all waste streams, as per Part III, Condition G, by adding a downstream point identified as "D". The toxicity testing sample location should also be identified as "D". 3. Footnote 2 on the second page should delete references to "more than one unit" as there is only one unit at this plant. In addition, it is requested that this paragraph require records of chlorine release times to be kept at the plant for inspection by DEM, rather than require the regular submittal of a routine and steady value each month in the monitoring reports. Outfall 003 - Chemical Metal Cleaning Wastes and Outfall 004 Low Volume Wastes The priority pollutants sampling is addressed by requirements'. on Outfall 001 and reference here should be deleted. Part III, Condition F - Toxicity Reopener CP&L believes that the word "shall" in the first sentence should be replaced with "may". This wording will allow a more flexable response by DEM after all relevant.factors.have been. considered.: Part III, Condition H - Toxicity Testing Requirement CP&L is particularly concerned about the proposed toxicity limits applicable to our effluents. Toxicity testing and the derivation of limits have not been subject to the -usual rulemaking process, including public review and comment prior to implementation. .In addition, CP&L is cautious of any such new limit when there has been little or no prior monitoring or other specific study to determine if, in fact, our effluent can meet this particular limit. Such an "end of pipe" toxicity limit is significantly different than the instream (4211CCW/dsm) -2 - effects that have been emphasized in most previous permits and biological monitoring efforts. Power plant design and most previous environmental assessments were not intended to address this specific type of NPDES limit. CP&L takes its responsibility to comply with all permit limits very seriously, and has strong reservations toward any new limit when the ability to comply is I1 not clear. While the purpose and necessity of toxicity monitoring is I(eel recognized, CP&L requests that an s ecific limit for toxicity be deferred until initial monitoring tests can be com leted and an can es in effluent characteristics that ma a necessar y to comp eva uated and implement d. The with a iven limit can be a ow to add specific toxicity limits at contains aslaterl date when entreopentauses o lrelative factors can be considered. If DEM decides to keep a toxicity limit in this permit, the following comments apply. Toxicity Limit - The draft permit contains the toxicity limit expressed as "no significant mortality in an effluent concentration of 95%". The effluent test A_ protocol that DEM cites is designed to provide dose -response data for estimating an LC50. The term "significant mortality" is not defined. CP&L 014 - requests that the toxicity limit be explicitly stated as "an LC50 not lower than an effluent concentration of.. 906 Date of first test - Since CP&L has not recently used the Fathead Minnow as a toxicity test organism, we may not be prepared to conduct the required tests x¢11/ in-house before the end of 1987. It is requested that the requirement for (y l\ performance of the first test be changed from 30 days to 90 days after issuance of this permit to allow adequate preparation. Test Variability - CP&L requests that NCDEM take into account both the effluent toxicity test method variability and individual test precision when a) setting the effluent toxicity limit, and b) interpreting the results of an individual test with respect to the permit toxicity limit. a) The draft permit contains no reference to the inherent variability of the acute toxicity test method. The toxicology literature provides some estimates of coefficients of variation (CV) for acute toxicity tests that N D generally range from 25% to 40%. CP&L believes it reasonable that the 'u variability of the test method be incorporated into the permit toxicity limit so that any routine test of an effluent sample not cause the permit limit to be failed simply due to random error associated with the toxicity test method. b) Given that the permit toxicity limit will be expressed as an LC50 (see above), CP&L requests that the permit explicitly state that the LC50 confidence interval of any individual test be considered as the unit for comparison to the permit toxicity limit. Methods for calculating the LC50 point estimate from a set of toxicity data include estimation of the confidence interval around the LC50. The toxicity test reporting form (DEM Form AT -1) suggests methods for calculating the LC50 and an associated confidence interval and requests that the confidence interval be reported. The confidence interval represents the range of values within which the "true" LC50 lies based on statistical certainty. Because the true LC50 lies anywhere within the confidence interval it is the interval itself and not the LC50 point estimate that should be compared to the permit toxicity limit. Therefore, a permit limit violation would occur (4211CCW/dsm) �• . -3- only if the upper limit of the LC50 confidence interval was less than the Permit toxicity limit. Viewing the results in this fashion would minimize the occurrence of false positives (declaring the effluent sample toxicity a violation when actual toxicity was less than the permit allows). Part III, Condition G - Priority Pollutant Monitoring Regarding the monitoring requirement for "priority pollutants", CP&L questions if such monitoring is necessary. Effluent characteristics for the steam electric industry have been thoroughly investigated and identified by EPA, DEM, and the industry itself. As part of the NPDES renewal process, a thorough analysis for such priority pollutants is conducted every 5 years. In addition, if any of the referenced pollutants are added by the Company, DEM is notified in advance and approval obtained if necessary. This process provides adequate assurances that any listed chemical is properly accounted for or not present at all. CP&L expects to request that this requirement be deleted after two or three years of monitoring have demonstrated that there is no additional information to be gained from the expense and effort required to comply. 910 Additional Items Please add a condition in Part III that will allow the use of upsets as a defense for noncompliance with technology based effluent limits as per 40 CFR 122.41. (4211CCW/dsm) -v r ''I�