Section 390. Effluent sampling procedures

State permit applicants for discharges from large and small municipal storm sewers or municipal storm sewers designated under 9VAC25-870-380 A 1 e shall provide the following information to the department, using application forms provided by the department.

A. Information on stormwater discharges that is to be provided as specified in 9VAC25-870-380. When quantitative data for a pollutant are required, the state permit applicant must collect a sample of effluent and analyze it for the pollutant in accordance with analytical methods approved under 40 CFR Part 136. When no analytical method is approved the state permit applicant may use any suitable method but must provide a description of the method. When an a state permit applicant has two or more outfalls with substantially identical effluents, the board may allow the state permit applicant to test only one outfall and report that the quantitative data also apply to the substantially identical outfalls. The requirements in subsections E and F of this section that a state permit applicant must provide quantitative data for certain pollutants known or believed to be present do not apply to pollutants present in a discharge solely as the result of their presence in intake water; however, an applicant must report such pollutants as present. Grab samples must be used for pH, temperature, cyanide, total phenols, residual chlorine, oil and grease, fecal coliform, and fecal streptococcus. For all other pollutants, 24-hour composite samples must be used. However, a minimum of one grab sample may be taken for effluents from holding ponds or other impoundments with a retention period greater than 24 hours. In addition, for discharges other than stormwater discharges, the board may waive composite sampling for any outfall for which the state permit applicant demonstrates that the use of an automatic sampler is infeasible and that the minimum of four grab samples will be a representative sample of the effluent being discharged.

B. For stormwater discharges, all samples shall be collected from the discharge resulting from a storm event that is greater than 0.1 inch and at least 72 hours from the previously measurable (greater than 0.1 inch rainfall) storm event. Where feasible, the variance in the duration of the event and the total rainfall of the event should not exceed 50% from the average or median rainfall event in that area. For all state permit applicants, a flow-weighted composite shall be taken for either the entire discharge or for the first three hours of the discharge. The flow-weighted composite sample for a stormwater discharge may be taken with a continuous sampler or as a combination of a minimum of three sample aliquots taken in each hour of discharge for the entire discharge or for the first three hours of the discharge, with each aliquot being separated by a minimum period of 15 minutes. However, a minimum of one grab sample may be taken for stormwater discharges from holding ponds or other impoundments with a retention period greater than 24 hours. For a flow-weighted composite sample, only one analysis of the composite of aliquots is required. For stormwater discharge samples taken from discharges associated with industrial activities, quantitative data must be reported for the grab sample taken during the first 30 minutes (or as soon thereafter as practicable) of the discharge for all pollutants specified in 9VAC25-870-380 C 1. For all stormwater state permit applicants taking flow-weighted composites, quantitative data must be reported for all pollutants specified in 9VAC25-870-380 except pH, temperature, cyanide, total phenols, residual chlorine, oil and grease, fecal coliform, and fecal streptococcus. The board may allow or establish appropriate site-specific sampling procedures or requirements, including sampling locations, the season in which the sampling takes place, the minimum duration between the previous measurable storm event and the storm event sampled, the minimum or maximum level of precipitation required for an appropriate storm event, the form of precipitation sampled (snow melt or rain fall), protocols for collecting samples under 40 CFR Part 136, and additional time for submitting data on a case-by-case basis. A state permit applicant is expected to know or have reason to believe that a pollutant is present in an effluent based on an evaluation of the expected use, production, or storage of the pollutant, or on any previous analyses for the pollutant. (For example, any pesticide manufactured by a facility may be expected to be present in contaminated stormwater runoff from the facility.)

C. Every state permit applicant must report quantitative data for every outfall for the following pollutants:

Biochemical oxygen demand (BOD₅)

Chemical oxygen demand

Total organic carbon

Total suspended solids

Ammonia (as N)

Temperature (both winter and summer)

pH

D. The board may waive the reporting requirements for individual point sources or for a particular industry category for one or more of the pollutants listed in subsection C of this section if the state permit applicant has demonstrated that such a waiver is appropriate because information adequate to support issuance of a state permit can be obtained with less stringent requirements.

E. Each state permit applicant with processes in one or more primary industry category (see 40 CFR Part 122 Appendix A) contributing to a discharge must report quantitative data for the following pollutants in each outfall containing process wastewater:

1. The organic toxic pollutants in the fractions designated in Table I of 40 CFR Part 122 Appendix D for the state permit applicant's industrial category or categories unless the state permit applicant qualifies as a small business. Table II of 40 CFR Part 122 Appendix D lists the organic toxic pollutants in each fraction. The fractions result from the sample preparation required by the analytical procedure that uses gas chromatography/mass spectrometry. A determination that a state permit applicant falls within a particular industrial category for the purposes of selecting fractions for testing is not conclusive as to the state permit applicant's inclusion in that category for any other purposes; and

2. The pollutants listed in Table III of 40 CFR Part 122 Appendix D (the toxic metals, cyanide, and total phenols).

F. 1. Each state permit applicant must indicate whether it knows or has reason to believe that any of the pollutants in Table IV of 40 CFR Part 122 Appendix D (certain conventional and nonconventional pollutants) is discharged from each outfall. If an applicable effluent limitations guideline either directly limits the pollutant or, by its express terms, indirectly limits the pollutant through limitations on an indicator, the state permit applicant must report quantitative data. For every pollutant discharged that is not so limited in an effluent limitations guideline, the state permit applicant must either report quantitative data or briefly describe the reasons the pollutant is expected to be discharged.

2. Each applicant must indicate whether it knows or has reason to believe that any of the pollutants listed in Table II or Table III of 40 CFR Part 122 Appendix D (the toxic pollutants and total phenols) for which quantitative data are not otherwise required under subsection E of this section, is discharged from each outfall. For every pollutant expected to be discharged in concentrations of 10 ppb or greater the state permit applicant must report quantitative data. For acrolein, acrylonitrile, 2,4 dinitrophenol, and 2-methyl-4,6 dinitrophenol, where any of these four pollutants are expected to be discharged in concentrations of 100 ppb or greater the state permit applicant must report quantitative data. For every pollutant expected to be discharged in concentrations less than 10 ppb, or in the case of acrolein, acrylonitrile, 2,4 dinitrophenol, and 2-methyl-4,6 dinitrophenol, in concentrations less than 100 ppb, the state permit applicant must either submit quantitative data or briefly describe the reasons the pollutant is expected to be discharged. A state permit applicant qualifying as a small business is not required to analyze for pollutants listed in Table II of 40 CFR Part 122 Appendix D (the organic toxic pollutants).

G. Each state permit applicant must indicate whether it knows or has reason to believe that any of the pollutants in Table V of 40 CFR Part 122 Appendix D (certain hazardous substances and asbestos) are discharged from each outfall. For every pollutant expected to be discharged, the state permit applicant must briefly describe the reasons the pollutant is expected to be discharged, and report any quantitative data it has for any pollutant.

H. Each state permit applicant must report qualitative data, generated using a screening procedure not calibrated with analytical standards, for 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) if it:

1. Uses or manufactures 2,4,5-trichlorophenoxy acetic acid (2,4,5,-T); 2-(2,4,5-trichlorophenoxy) propanoic acid (Silvex, 2,4,5,-TP); 2-(2,4,5-trichlorophenoxy) ethyl, 2,2-dichloropropionate (Erbon); O,O-dimethyl O-(2,4,5-trichlorophenyl) phosphorothioate (Ronnel); 2,4,5-trichlorophenol (TCP); or hexachlorophene (HCP); or

2. Knows or has reason to believe that TCDD is or may be present in an effluent.

Historical Notes

Former 4VAC50-60-390 derived from Volume 21, Issue 03, eff. January 29, 2005; amended, Volume 29, Issue 04, eff. November 21, 2012; amended and renumbered, Virginia Register Volume 30, Issue 02, eff. October 23, 2013.

Statutory Authority

§§ 62.1-44.15:25 and 62.1-44.15:28 of the Code of Virginia.