Water quality criteria for toxic pollutants for zones 2 - 6 of the Delaware estuary, basis and background document

The Delaware River Basin Commission (DRBC) proposes to update stream quality objectives for human health and aquatic life in the tidal portion of the Delaware River Basin from the head of tide at Trenton, NJ to the Delaware Bay (Zones 2 through 5) and to adopt stream quality objectives for toxic pollutants to uniformly apply in the estuary to the mouth of the Delaware Bay (Zone 6). The objectives for Zones 2 through 5 appear in Section 3.30 of the Delaware River Basin Commission’s Administrative Manual Part III - Water Quality Regulations (18 CFR Part 410). The specific subsections of this regulation include Section 3.30.2 for Zone 2, Section 3.30.3 for Zone 3, Section 3.30.4 for Zone 4, and Section 3.30.5 for Zone 5. Tables 3 through 7 of the regulations include the numeric values of the objectives for the protection of the taste and odor of ingested water and fish, aquatic life and human health from the ingestion of water and fish. Section 3.30.6 is proposed to be modified to include references to the marine criteria in Tables 4 through 7 for Zone 6. Table 3 is not referenced in Section 3.30.6 since it only applies to Zones where drinking water is a designated use. Stream quality objectives (also referred to as water quality criteria) are specifications of the condition of ambient water which are designed to assure the protection of the designated use of a water body. The changes in criteria reflect new scientific information and harmonize DRBC criteria with basin states’ criteria.This report was revised December 2, 2010