NC0039586_Toxicity Monitoring Requirement for CP&L_19910507

DIVISION OF ENVIRONMENTAL MANAGEMENT _
May 7, 1991 jV
MEMORANDUM ��°t 1991
TO: Steve Tedder +/
THROUGH: Ken Eagleson
FROM: Larry Ausley I`
SUBJECT: Toxicity Monitoring Requirement for CP&L Shearon Harris Draft NPDES Permit
NC0039586 Pipe 006 Chatham County
The draft permit issued for this facility has originally been recommended including a 48 hour Daphnid
acute toxicity monitoring requirement. This recommendation reflects a modification in currently permitted
effluent testing, i.e. 48 hour fathead minnow acute testing as well as the -addition of pipes permitted as low
level radiation waste discharge, and sanitary waste. Neither of the additional pipes, would in and of
themselves, instigate addition of a toxicity limit or monitoring by current permitting practices. As we
currently have better than a year's worth of monthly fathead toxicity tests which, for the most part indicate
little or no acute toxicity, I feel that the recommended permit monitoring requirement could appropriately
remain the 48 hour fathead minnow acute toxicity test and that the draft permit requirement be modified as
such.
I have discussed this matter with Mr. Rick Yates of CP&L and Betsy Johnson of the Technical Support
Branch who are aware of this proposed modification. If I can provide you with additional information,
please advise.
cc: Dale Overcash
Betsy Johnson