Recent and Proposed Changes to Pa.’s Water Quality Standards

The Legal Inteligencer

(by Daniel Hido and Hannah Baldwin)

There have been several notable developments recently regarding the Pennsylvania Department of Environmental Protection’s (PADEP) water quality standards regulations at 25 Pa. Code Chapter 93. First, on Jan. 31, the Pennsylvania Independent Regulatory Review Commission (IRRC) approved updates set forth as part of PADEP’s triennial review of the state’s water quality standards. Second, significant changes to the water quality standard for manganese moved closer to becoming law when the Pennsylvania Environmental Quality Board (EQB), a 20-member independent board that reviews and adopts PADEP proposed regulations before publication for public comment, approved PADEP’s proposed rulemaking on Dec. 17, 2019. Finally, PADEP continues work on a final rulemaking with respect to several proposed Class A stream redesignations after receiving comments from the IRRC on June 6, 2019.

PADEP implements the Chapter 93 instream water quality standards by first setting designated uses of surface waterbodies in Pennsylvania, and then by implementing water quality-based effluent limitations in NPDES permits to achieve or maintain the instream water quality of the receiving water, where applicable. Thus, changes to the Chapter 93 water quality standards may result in new or revised effluent limits for any facility that holds an NPDES permit.

Updated Triennial Water Quality Standards

Under Section 303(c) of the Clean Water Act, 33 U.S.C. Section 1313(c), PADEP is required to review and modify, as appropriate, the state’s water quality standards at least every three years. The Chapter 93 water quality standards were last updated in July 2013. The current updates were first proposed in October 2017.

The revised water quality standards make several changes to Table 3 (specific water quality criteria) and Table 5 (human health and aquatic life criteria for toxic substances) in Chapter 93. First, PADEP updated the aquatic life water quality criteria for bacteria and ammonia in Table 3 to be consistent with the EPA’s updated 2012-2013 criteria, after PADEP determined that the EPA’s recommended criteria were appropriate for waters of the commonwealth.

Second, PADEP updated the human health criteria for several toxic pollutants in Table 5 to adopt the EPA’s 2015 recommended criteria. The changes create more stringent criteria for 55 toxic pollutants, set less stringent criteria for 18 toxic pollutants, and add an additional nine toxic pollutants to the table.

As part of the triennial review requirements, PADEP also re-evaluated two waterbodies in Pennsylvania that do not meet fishable or swimmable designated uses: the Harbor Basin and entrance channel to Outer Erie Harbor/Presque Isle Bay and several zones in the Delaware Estuary. PADEP ultimately did not revise either designation, finding that boating and commercial shipping hazards still exist in the Harbor Basin and entrance channel and opting to initiate an evaluation with the Delaware River Basin Commission (DRBC) to determine whether the designated use in the Delaware Estuary zones should be updated as part of the next triennial review.

PADEP and DRBC will also evaluate whether the designated use of certain zones of the Delaware River should be revised as part of the next triennial review to include fish propagation, and whether corresponding dissolved oxygen standards should be adjusted in response to evidence of recovery of fish propagation in those areas. The National Marine Fisheries Service recently designated the Delaware Estuary as a critical habitat under the Endangered Species Act for the endangered Atlantic sturgeon. This designation means that PADEP is required to ensure protection of the sturgeon in the Delaware Estuary. (See 25 Pa. Code Section 93.4c(a)(2)). PADEP indicated that it will fulfill this requirement on a case-by-case basis.

Finally, PADEP revised 25 Pa. Code Section 93.d(c) to clarify that the Biotic Ligand Model now must be used, rather than may be used, to develop new or updated site-specific criteria for copper in freshwater systems.

The updated standards will go into effect upon publication of the final rule in the Pennsylvania Bulletin.


On Dec. 17, 2019, the EQB approved the PADEP’s proposed rulemaking “Water Quality Standards for Manganese and Implementation.” This rulemaking is being developed pursuant to Act 40 of 2017 (P.L. 379, No. 40) which directed the EQB to promulgate regulations, by Jan. 18, 2018, requiring that the manganese water quality criterion must “be met, consistent with the exception in 25 Pa. Code Section 96.3(d).” Section 96.3(d) establishes the location of an existing or planned surface potable water supply withdrawal as the point of compliance for several constituents including sulfate, fluoride, and chloride.

PADEP has been applying the current manganese water quality criterion of 1.0 mg/L (which has been in place since 1967 and is codified in Table 3 in 25 Pa. Code Section 93.7) in NPDES permits under 25 Pa. Code Section 96.3(c) at the point of discharge, meaning the criterion must be achieved in all surface waters at least 99% of the time. Act 40 directed PADEP to propose a regulation changing the point of compliance to the intake of an existing or planned surface potable water supply withdrawal.

The amendments approved by the EQB in December 2019 would delete manganese from Table 3 and add it to Table 5. The proposal would also change the water quality criterion from 1.0 mg/L to 0.3 mg/L. PADEP will solicit public comment on whether the point of compliance should be at the point of an existing or planned surface potable water supply withdrawal, as directed by Act 40, or at the point of discharge as under current practice. A more stringent criterion and changed point of compliance may impose significant treatment costs on several industries including coal and noncoal mining, manufacturing and publicly owned wastewater treatment plants.

The proposed rule will be published for public comment in a forthcoming issue of the Pennsylvania Bulletin. PADEP recommended a 45-day public comment period, including one public hearing to be held in the Harrisburg area.

Mandamus Action

On March 29, 2019, Senate President Pro Tempore Joe Scarnati (R-Jefferson) and Sen. Gene Yaw (R-Lycoming), Majority Chair of the Senate Environmental and Natural Resources Committee, filed a mandamus petition with the Commonwealth Court to compel PADEP and the EQB to promulgate the proposed manganese regulation by the Act 40 January 2018 deadline. The court dismissed the petition on Nov. 29, 2019, finding that the legislators did not have standing for the challenge. The senators appealed the Commonwealth Court’s decision to the Pennsylvania Supreme Court on Dec. 11, 2019. Initial briefs are due in early March. The case is Scarnati v. Pennyslvania Department of Environmental Protection, 220 A.3d 723 (Pa. Cmmw. Ct. 2019), appeal docketed, 94 MAP 2019 (Pa. Dec. 11 2019).

Stream Redesignations

PADEP is also drafting a final rulemaking to change the current designated use of 42 stream segments totaling 204 stream miles to high quality based on data submitted by the Pennsylvania Fish and Boat Commission regarding the streams’ classifications as wild trout streams, as well as PADEP’s conclusion that the high quality criteria for these stream segments were met. The proposed rule was published in the Pennsylvania Bulletin on March 23, 2019. IRRC commented on the proposed rule on June 6, 2019, requesting that EQB evaluate the additional Fish Commission data because it may increase the number of stream miles that would be affected by the rule.

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Reprinted with permission from the March 19, 2020 edition of The Legal Intelligencer© 2020 ALM Media Properties, LLC. All rights reserved.