25 Pa. Code § 16.51 - Human health and aquatic life criteria

(a) Chapter 93, Table 5 lists the human health and aquatic life criteria for toxic substances which the Department uses in development of effluent limitations in NPDES Permits and for other purposes. The Department will maintain a table of site-specific human health and aquatic life criteria that have been developed or reviewed and approved by the Department. The approved analytical procedures and detection limits for these substances will be listed, as appropriate, in Table 2A. The human health criteria, which include exposures from drinking water and fish consumption, are further defined as to the specific effect (that is, cancer or threshold health effects). For those aquatic life criteria which are a function of local water quality conditions and are specified as a formula, such as several of the heavy metals, the hardness and pH values used to derive the appropriate water quality criteria will be determined by instream measurements or best estimates, representative of the median concentrations or conditions of the receiving stream for the applicable time period and design conditions on a case-by-case basis. Some of these criteria may be superseded for the Delaware Estuary, Ohio River Basin, Lake Erie Basin, and Genesee River Basin under interstate and international compact agreements with the Delaware River Basin Commission, Ohio River Valley Sanitation Commission and International Joint Commission respectively. The toxics substances in Chapter 93, Table 5 without a PP NO are State-derived criteria. Water quality criteria for the Great Lakes System are in § 93.8e, Tables 6 and 7. Criteria in § 93.8c, Table 5 may apply to the Great Lakes System for those substances not listed in Table 6. Criteria may be developed for the Great Lakes System for substances other than those listed in Table 5 or 6 under the methodologies in § 16.61 (relating to special provisions for the Great Lakes System).

(b) If the Department determines that the natural quality of a surface water segment is of lower quality than the applicable criteria listed in Chapter 93, Table 5, the natural quality shall constitute the aquatic life criterion for that segment. Notice of all draft natural quality determinations shall be published in the Pennsylvania Bulletin and be subject to a minimum 45-day comment period. The Department will maintain a publicly available list of surface waters and parameters where this subsection applies, and will, from time to time, submit appropriate amendments to these chapters. Natural quality determinations are documented in stream investigation reports or water quality criteria rationale documents.

Notes

25 Pa. Code § 16.51

The provisions of this § 16.51 adopted March 10, 1989, effective 3/11/1989, 19 Pa.B. 1059; amended December 21, 1990, effective 12/22/1990, 20 Pa.B. 6299; amended November 17, 1995, effective 11/18/1995, 25 Pa.B. 5067; amended December 26, 1997, effective 12/27/1997, 27 Pa.B. 6817; amended November 17, 2000, effective 11/18/2000, 30 Pa.B. 6111; amended May 15, 2009, effective 5/16/2009, 39 Pa.B. 2543; amended July 10, 2020, effective 7/11/2020, 50 Pa.B. 3485.