9 Va. Admin. Code § 25-790-260

Current through Register Vol. 40, No. 22, June 17, 2024

Section 9VAC25-790-260 - Influent and effluent monitoring

A. Methods. Sampling and testing methods shall conform to permit requirements, or if not specified, to current United States Environmental Protection Agency (EPA) guidelines establishing test procedures for analysis of pollutants or other EPA approved methods.

B. Schedule. The operation and maintenance manual shall contain a specific testing schedule of the minimum tests and their frequencies to be conducted by the facility in accordance with the appropriate certificate and permit issued. If not specifically addressed in the issued certificate and permit, influent and effluent monitoring shall be in accordance with this schedule. Typical tests are listed in 9VAC25-790-960.

C. Sampling. The following sampling instructions shall be followed when collecting samples as required to comply with this chapter and standards contained in this chapter.

1. Raw sewage samples are be collected prior to the treatment process unit operations; samples may be collected following the bar screen or comminutor.

2. Final effluent samples are to be taken at a point following all unit operations in the treatment process. An evaluation of chlorine reduction or dechlorination methods will require monitoring of chlorine residual and fecal coliform levels in treated sewage flows following the chlorine contact tank.

3. Chlorine residual, fecal coliform, pH, temperature and DO test samples may consist of grab samples of sewage flow obtained immediately prior to analytical measurements.

4. Compositing of samples shall be in accordance with the treatment works operation and maintenance manual. Composite samples of sewage flows shall consist of grab samples taken at a minimum frequency of one per hour and should be combined in proportion to flow. Greater frequency of grab sampling may be desirable where abnormal variation in waste strength occurs. Automatic flow proportional samplers are considered a valid sampling method.

9 Va. Admin. Code § 25-790-260

Former 12VAC5-581-320 derived from Virginia Register Volume 18, Issue 10, eff. February 27, 2002; amended and adopted as 9VAC25-790-260, Virginia Register Volume 20, Issue 9, eff. February 12, 2004.

Statutory Authority

§ 62.1-44.19 of the Code of Virginia.