New York State Water Quality Standards (WQS)

DEC code (law) for NYS WQS

This document includes information about New York State water quality laws. Try to integrate these classifications and standards into your comments. ( Download a pdf of this file here.)

All streams are classified for their best uses (fishing, swimming, drinking water, etc.). The DEC then applies standards (and guidance) to protect those uses.

The DEC refers to surface waters (rivers, streams, etc.) by their alphabetical code (AA, B, T, etc.). Each has its own level of protection. So when you discuss a stream, mention its classification, and then describe how building the pipeline would degrade its best use.

You can also describe how building the pipeline would violate narrative water quality standards for different classes of streams. These standards are in § 703.


Will hay and silt fences stop the flow of turbid water?For example, constructing the pipeline will require clear-cutting trees and digging trenches on steep slopes in clay soil. This will cause runoff, making streams muddy – or turbid. For AA, A, B, C, and D streams, there can be no increase in turbidity “that will cause a substantial visible contrast to natural conditions.” (See row 2, column 3.) How can they build a pipeline and not have muddy water downstream? Will hay and silt fences stop the flow of turbid water? Describe why FERC’s “best management practices” (BMPs), such as silt fences, will not be effective in protecting water quality along the route.

NYS Water Quality Standards

Under the Clean Water Act (CWA), states establish water quality standards (WQS). DEC enforces the CWA in NYS, and has to certify the project won’t violate our WQS.

First you need to learn the classifications of surface waters, and their best uses. Below are the ones that are found along the pipeline route in NYS (AA, B, C, D, T, TS). There is not supposed to be any degradation of water quality.


New York Water Quality Classifications

6 NYCRR § 700 – New York Codes, Rules, and Regulations (NYCRR)

§ 701.1 General conditions applying to all water classifications

The discharge of sewage, industrial waste or other wastes shall not cause impairment of the best usages of the receiving water as specified by the water classifications at the location of discharge and at other locations that may be affected by such discharge.

Class AA fresh surface waters

  1. The best usages of Class AA waters are: a source of water supply for drinking, culinary or food processing purposes; primary and secondary contact recreation; and fishing. The waters shall be suitable for fish, shellfish, and wildlife propagation and survival.

  2. This classification may be given to those waters that, if subjected to approved disinfection treatment, with additi