Title of Regulation: 9VAC25-260. Water Quality Standards (amending 9VAC25-260-185).

Statutory Authority: § 62.1-44.15 of the Code of Virginia; Clean Water Act (33 USC § 1251 et seq.); 40 CFR Part 131.

Public Hearing Information: No public hearings are scheduled.

Public Comment Deadline: December 26, 2018.

Effective Date: January 10, 2019.

Agency Contact: Tish Robertson, Department of Environmental Quality, 1111 East Main Street, Suite 1400, P.O. Box 1105, Richmond, VA 23218, telephone (804) 698-4309, FAX (804) 698-4116, or email tish.robertson@deq.virginia.gov.

Basis: Section 62.1-44.15 of the Code of Virginia mandates and authorizes the State Water Control Board to establish water quality standards and policies for any state waters consistent with the purpose and general policy of the State Water Control Law and to modify, amend, or cancel any such standards or policies established. Section 303(c) of the federal Clean Water Act mandates the State Water Control Board to review and, as appropriate, modify and adopt water quality standards. The corresponding federal water quality standards regulation at 40 CFR 131.6 describes the minimum requirements for water quality standards. The minimum requirements are use designations, water quality criteria to protect the designated uses, and an antidegradation policy. These are all mandates for water quality standards.

The Environmental Protection Agency (EPA) Water Quality Standards regulation (40 CFR 131. 11) is the regulatory basis for the EPA requiring the states to establish water quality criteria to protect designated uses, and the criteria are used to assess whether or not a waterbody is meeting those uses.

Purpose: The department has concluded that the proposed amendments to the regulation are essential to protecting the health, safety, and welfare of the citizens of the Commonwealth by protecting the water quality and living resources of the Chesapeake Bay and its tidal rivers. EPA has continued to refine the assessment procedures as scientific research and management applications reveal new insights and knowledge about the Chesapeake Bay. The EPA's procedure documents being incorporated into Virginia's regulation by this action replace or otherwise supersede similar criteria assessment procedures published in earlier documents, but not all of them. Therefore, it is necessary for the Virginia water quality standards to refer to each of the addenda published by EPA.

Rationale for Using Fast-Track Rulemaking Process: The proposed amendment to 9VAC25-260-185 B references assessment protocol documents published by EPA. These protocols have been developed by EPA through a collaborative process within the Chesapeake Bay Program. There have been several other similar technical addenda incorporated into Virginia's Water Quality Standards Regulation using the fast-track rulemaking procedure without opposition due to their noncontroversial nature since the Chesapeake Bay water quality criteria were originally adopted by the State Water Control Board in 2005.

Substance: The proposed substantive amendment to 9VAC25-260-185 B of the Water Quality Standards is a reference to the November 2017 Chesapeake Bay Criteria Assessment Protocols Addendum. These recently published protocols direct how Chesapeake Bay dissolved oxygen criteria should be assessed. Therefore, it is necessary for the Virginia Water Quality Standards to refer to this document.

Issues: There are no primary advantages or disadvantages to the public. The primary advantage to the agency and the Commonwealth is having improved methods for assessing attainment of designated uses in the Chesapeake Bay. There is no disadvantage to the agency or the Commonwealth that will result from the adoption of this amendment.

Department of Planning and Budget's Economic Impact Analysis:

Summary of the Proposed Amendments to Regulation. The State Water Control Board (Board) proposes to incorporate by reference the most recent U.S. Environmental Protection Agency (EPA) assessment methodology for the Chesapeake Bay nutrient criteria.¹

Result of Analysis. The benefits likely exceed the costs for all proposed changes.

Estimated Economic Impact. This regulation incorporates by reference the procedures to be followed when assessing the nutrient criteria in the Chesapeake Bay. These assessment procedures are frequently refined by the EPA as scientific research and management applications reveal new insights and knowledge about the Chesapeake Bay. According to the Department of Environmental Quality, there is no substantive difference between what is currently followed in practice and what is being prescribed in the updated procedures document proposed for incorporation by reference. However, the updated document contains procedures for assessment of short-duration dissolved oxygen criteria, which did not exist before. Currently, due to lack of resources, there is nothing being done in Virginia to assess the short-duration dissolved oxygen criteria. Therefore, the incorporation of the new assessment procedures would not have any immediate impact but would be beneficial when and if Virginia moves forward to assess short-duration dissolved oxygen criteria.

Businesses and Entities Affected. Currently, there are 139 point sources this regulation applies to. All but three are water treatment plants.

Localities Particularly Affected. The proposed amendment does not affect any particular locality more than others.

Projected Impact on Employment. The proposed amendment does not have any effect on employment.

Effects on the Use and Value of Private Property. The proposed amendment does not have any effect on the use and value of private property.

Real Estate Development Costs. No impact on real estate development costs is expected.

Small Businesses:

Definition. Pursuant to § 2.2-4007.04 of the Code of Virginia, small business is defined as "a business entity, including its affiliates, that (i) is independently owned and operated and (ii) employs fewer than 500 full-time employees or has gross annual sales of less than $6 million."

Costs and Other Effects. The proposed amendment applies to only three small businesses, but no effect on them is expected.

Alternative Method that Minimizes Adverse Impact. The proposed amendment does not have adverse effects on small businesses.

Adverse Impacts:

Businesses. The proposed amendment does not have adverse impacts on businesses.

Localities. The proposed amendment will not adversely affect localities.

Other Entities. The proposed amendment will not adversely affect other entities.

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¹See Ambient Water Quality Criteria for Dissolved Oxygen, Water Clarity and Chlorophyll a for the Chesapeake Bay and Its Tidal Tributaries - 2017 Technical Addendum, EPA 903-R-17-002, CB/TRS 320-17, November 2017, U.S. EPA Region III Chesapeake Bay Office. Accessed online at www.chesapeakebay.net/documents/2017_Nov_ChesBayWQ_Criteria_Addendum_Final.pdf on May 17, 2018.

Agency's Response to Economic Impact Analysis: The department has reviewed the economic impact analysis prepared by the Department of Planning and Budget and has no comment.

Summary:

The amendment incorporates by reference the Chesapeake Bay Criteria Assessment Protocols Addendum published in November 2017 by the U.S. Environmental Protection Agency on behalf of the Chesapeake Bay Program partnership.

9VAC25-260-185. Criteria to protect designated uses from the impacts of nutrients and suspended sediment in the Chesapeake Bay and its tidal tributaries.

A. Dissolved oxygen. The dissolved oxygen criteria in the below following table apply to all Chesapeake Bay waters according to their specified designated use and supersede the dissolved oxygen criteria in 9VAC25-260-50.

B. Submerged aquatic vegetation (SAV) and water clarity. Attainment of the shallow-water submerged aquatic vegetation designated use shall be determined using any one of the following criteria:

C. Chlorophyll a.

D. Implementation.

1. Chesapeake Bay program segmentation scheme as described in Chesapeake Bay Program, 2004 Chesapeake Bay Program Analytical Segmentation Scheme-Revisions, Decisions and Rationales: 1983–2003, CBP/TRS 268/04, EPA 903‑R‑04‑008, Chesapeake Bay Program, Annapolis, Maryland, and the Chesapeake Bay Program published 2005 addendum (CBP/TRS 278‑06; EPA 903‑R‑05‑004) is listed below in the following table and shall be used as the spatial assessment unit to determine attainment of the criteria in this section for each designated use.

2. The assessment period shall be the most recent three consecutive years. When three consecutive years of data are not available, a minimum of three years within the data assessment window shall be used.

3. Attainment of these criteria shall be assessed through comparison of the generated cumulative frequency distribution of the monitoring data to the applicable criteria reference curve for each designated use. If the monitoring data cumulative frequency curve is completely contained inside the reference curve, then the segment is in attainment of the designated use. The reference curves and procedures to be followed are published in the USEPA, Ambient Water Quality Criteria for Dissolved Oxygen, Water Clarity and Chlorophyll a for the Chesapeake Bay and Its Tidal Tributaries, EPA 903‑R‑03‑002, April 2003 and the 2004 (EPA 903‑R‑03‑002 October 2004), 2007 (CBP/TRS 285‑07 285/07, EPA 903‑R‑07‑003), 2007 (CBP/TRS 288/07, EPA 903‑R‑07‑005), 2008 (CBP/TRS 290‑08, EPA 903‑R‑08‑001), and 2010 (CBP/TRS 301‑10, EPA 903‑R‑10‑002), and 2017 (CBP/TRS 320‑17, EPA 903‑R‑17‑002) addenda. An exception to this requirement is in measuring attainment of the SAV and water clarity acres, which are compared directly to the criteria.

DOCUMENTS INCORPORATED BY REFERENCE (9VAC25-260)

Chesapeake Bay Program Analytical Segmentation Scheme - Revisions, Decisions and Rationales 1983‑2003, EPA 903‑R‑04‑008, CBP/TRS 268/04, October 2004, US EPA Region III Chesapeake Bay Office.

Chesapeake Bay Program Analytical Segmentation Scheme - Revisions, Decisions and Rationales 1983‑2003, EPA 903‑R‑05‑004, CBP/TRS 278‑06, 2005 Addendum, December 2005, US EPA Region III Chesapeake Bay Office.

Ambient Water Quality Criteria for Dissolved Oxygen, Water Clarity and Chlorophyll a for the Chesapeake Bay and Its Tidal Tributaries, EPA 903‑R‑03‑002, April 2003 and 2004 Addendum, October 2004, US EPA Region III Chesapeake Bay Office

Ambient Water Quality Criteria for Dissolved Oxygen, Water Clarity and Chlorophyll a for the Chesapeake Bay and Its Tidal Tributaries, EPA 903‑R‑07‑003, CBP/TRS 285/07 2007 Addendum, July 2007, US EPA Region III Chesapeake Bay Office.

Technical Support Document for Identification of Chesapeake Bay Designated Uses and Attainability, EPA 903‑R‑03‑004, October 2003 and 2004 Addendum, October 2004, US EPA Region III Chesapeake Bay Office.

Ambient Water Quality Criteria for Dissolved Oxygen, Water Clarity and Chlorophyll a for the Chesapeake Bay and its Tidal Tributaries - 2007 Chlorophyll Criteria Addendum, EPA 903‑R‑07‑005, CBP/TRS 288/07, November 2007, U.S. EPA Region III Chesapeake Bay Office.

Ambient Water Quality Criteria for Dissolved Oxygen, Water Clarity and Chlorophyll a for the Chesapeake Bay and its Tidal Tributaries - 2008 Technical Support for Criteria Assessment Protocols Addendum, EPA 903‑R‑08‑001, CBP/TRS 290‑08, September 2008, U.S. EPA Region III Chesapeake Bay Office.

Ambient Water Quality Criteria for Dissolved Oxygen, Water Clarity and Chlorophyll a for the Chesapeake Bay and its Tidal Tributaries - 2010 Technical Support for Criteria Assessment Protocols Addendum, EPA 903‑R‑10‑002, CBP/TRS 301‑10, May 2010, U.S. EPA Region III Chesapeake Bay Office.

Ambient Water Quality Criteria for Dissolved Oxygen, Water Clarity and Chlorophyll a for the Chesapeake Bay and Its Tidal Tributaries - 2017 Technical Addendum, EPA 903‑R‑17‑002, CBP/TRS 320‑17, November 2017, U.S. EPA Region III Chesapeake Bay Office