250 R.I. Code R. 250-RICR-150-05-1.27

Current through November 7, 2024

Section 250-RICR-150-05-1.27 - The Implementation of the Antidegradation Provisions of the Rhode Island Water Quality Regulations

A. Introduction - Antidegradation Standard

1. § 1.20 of this Part is based on the Federal Antidegradation Policy requirements, 40 C.F.R. § 131.12 and adopted under the authority of R.I. Gen. Laws Chapters 46-12, 42-17.1 and 42-35.

2. Antidegradation is one of the minimum elements required in state water quality standards. The provisions of the State Antidegradation Regulations have as their objective the maintenance and protection of various levels of water quality and uses.

3. The Rhode Island Antidegradation provisions consist of four (4) tiers of water quality protection which are defined in general terms in § 1.20 of this Part.

B. Applicability - Antidegradation applies to all new or increased projects or activities which may lower water quality or affect existing water uses, including but not limited to all 401 Water Quality Certification reviews and any new, reissued, or modified RIPDES permits. This Antidegradation Implementation Policy describes the general strategy the State will use to determine on a case-by-case basis whether, and to what extent, water quality may be lowered.

C. Preconditions for Implementation of Antidegradation Procedures

1. At the onset of the antidegradation review, a determination by the State, of whether the proposed activity can be considered a new or increased activity, must be made.

a. A new activity in terms of application of this Antidegradation Implementation Policy shall refer to any activity which commenced after November 28, 1975.

b. An increased activity shall refer to:

(1) A proposed increase in loadings to a waterbody.

(2) For discharges covered by existing RIPDES permits an evaluation of an increased loading shall constitute a comparison of the present permit limit with the newly calculated permit limit. If the new permit limit is less than or equal to the old limit, it would not be considered an increased activity. If the comparison indicates that the new permit limit is greater than the old limit, it would be considered an increased activity.

(3) An increase in a flow alteration over the existing use.

2. If the above evaluations result in a determination that the proposed activity is not a new or increased activity, then there would be no further review of the proposed activity under the Antidegradation Implementation Policy. If the above evaluations result in a determination that the proposed activity is a new or increased activity, then the activity will be reviewed for consistency with this Antidegradation Implementation Policy.

D. Antidegradation Protections for Tier 1 and Tier 2

1. Tier 1 - Protection of Existing Uses

a. General - This provision applies to all surface waters.

(1) An existing use can be established by demonstrating that a use(s) has actually occurred since November 28, 1975, and the water quality is suitable to allow the existing use or;

(2) By demonstrating that although a designated use(s) has not occurred the water quality is suitable to allow such a use(s) to occur, unless there are physical problems which prevent the use and which cannot be remedied.

b. Under Tier 1, a proposed activity or discharge cannot partially or completely eliminate any existing uses nor the water quality needed to maintain and protect those uses.

c. The proposed activity cannot violate the class-specific criteria for minimum water quality of the assigned water quality standard of a waterbody.

(1) The more stringent of instream aquatic life criteria or applicable human health criteria for toxic pollutants must be met in all waters, regardless of the classification.

d. The Department may make requests for evidence/data for applications of proposed activities or discharges in accordance with § 1.27(E)(3) of this Part.

2. Tier 2 - Protection of Water Quality in High Quality Waters

a. General - In a waterbody where, for any parameter, the existing water quality exceeds that level necessary to support the propagation of fish and wildlife and recreation in and on the waters, regardless of the use designation, that water shall be considered high quality for that parameter.

(1) All parameters do not need to be better quality than the ambient criteria for the water to be deemed a "high quality water". Instead, a waterbody is assessed as being high quality on a parameter-by-parameter basis.

b. That high quality shall be maintained and protected, except for insignificant changes in water quality as determined by the Director and in accordance with § 1.27(E) of this Part.

c. Significant changes in water quality may be allowed if it can be proven to the Director by a preponderance of clear and scientifically valid evidence having a probative value, and the Director finds, after full satisfaction of the intergovernmental coordination and public participation provisions of the RI Continuing Planning Process, that allowing the water quality degradation is necessary to accommodate important economic and social benefit in the area in which the receiving waters are located § 1.27(E)(5) of this Part.

(1) In allowing any such significant change in water quality, the Director shall assure water quality adequate to fully protect existing and designated uses.

d. In allowing a change in water quality, significant or insignificant, all reasonable measures to minimize the change shall be implemented.

(1) Adequate scientifically valid documentation shall demonstrate that existing and designated uses, water quality to protect those uses, and all applicable water quality standards, will be fully protected.

(2) Achievement of the highest statutory and regulatory requirements for all new and existing point sources and all cost effective and reasonable best management practices for nonpoint source controls, shall be assured.

3. Special Resource Protection Water - If the waterbody is a Special Resource Protection Water (SRPW), a special subset of High Quality Waters, additional requirements appear in Tier 2 1/2 of this Antidegradation Policy.

4. Outstanding National Resource Water - If the waterbody is an Outstanding National Resource Water (ONRW), a special subset of High Quality Waters, additional requirements appear in Tier 3 of this Antidegradation Policy.

E. Assessment Process for Determining Special Resource Protection and Outstanding National Resource Waters

1. Assess waterbody for high quality on a parameter-by-parameter basis:

a. Characterize the existing instream water quality and compare to the State's instream water quality criteria to assess for high quality water on a parameter-by-parameter basis.

(1) Instream water quality is characterized by the applicable flows associated with the most adverse conditions as stated in § 1.10(C) of this Part, background water quality levels (as determined by the Director), and all point source loadings and nonpoint source contributions and in accordance with § 1.12(B) of this Part.

(2) If this analysis indicates that the water is not high quality, then Tier 1 of the policy is the applicable level of protection.

(3) If this analysis indicates that the water is high quality, then continue with the Tier 2 antidegradation evaluation.

2. Define the remaining assimilative capacity of the receiving water:

a. The remaining assimilative capacity or buffer of the receiving water is equivalent to the difference between the State's instream water quality criteria and the existing instream water quality.

3. Request and obtain evidence/data for applications involving activities potentially impacting High Quality Waters:

a. If it is determined that a high quality water is involved in a request for an approval of a discharge or other activity, and sufficient supplemental data is not available, RIDEM may request that the applicant provide, at a minimum, the following information prepared by a qualified professional. All engineering analyses and documentation must be prepared, stamped, and signed by a professional engineer registered in the State pursuant to R.I. Gen. Laws Chapter 5-8. All biological and scientific analyses and documentation shall be prepared by individuals qualified in the scientific field.

(1) Adequate recent instream water quality data, and engineering analyses to calculate probable water quality impacts due to the discharge or activity, and evidence that the existing instream water uses, and the level of water quality necessary to protect those uses will be maintained and protected.

(2) Adequate scientific/engineering-based evidence describing the magnitude and duration of any lowering of water quality due to the discharge or activity by itself, and in combination with other discharges or activities presently occurring. Such evidence must also show that all water quality criteria applicable to the High Quality Water in question will not be violated.

(3) All documentation required by any other applicable RI Water Quality Regulation or which the Director determines is necessary.

(4) Where RIDEM determines that the information/documentation provided by the applicant is insufficient to make a valid determination, the Department has the authority to require additional information from the applicant before a decision is made. Failure to provide the required information shall result in denial of all approvals for the activity or discharge.

4. Determine if the discharge or activity will significantly impact the waterbody:

a. For any water quality parameter, increments of water quality within any High Quality Water which exceed the minimum water quality criteria of that water's assigned water quality standard. Degradation of water quality increments by the applicant shall only be allowed if the extent of degradation expected can be adequately documented, and it can be demonstrated by the applicant through full intergovernmental coordination and public participation process that the discharge or activity is necessary to achieve important economic or social benefit to the State, as required in § 1.27(D)(2) of this Part.

b. Any new or increased discharge or activity could lower existing water quality and thus require the important benefit demonstration. RIDEM will:

(1) Evaluate applications on a case-by-case basis, using BPJ and all pertinent and available facts, including scientific and technical data and calculations as provided by the applicant; and

(2) Determine whether the incremental loss is significant enough to require the important benefits demonstration described below.

c. Some of the considerations which will be made to determine if an impact is significant in each site specific decision are:

(1) Percent change in water quality parameter value and their temporal distribution;

(2) Quality and value of the resource;

(3) Cumulative impact of discharges and activities on water quality to-date;

(4) Measurability of the change;

(5) Visibility of the change;

(6) Impact on fish and wildlife habitat; and

(7) Impact on potential and existing uses.

d. As a general guide, any discharge or activity which consumes greater than 20% of the remaining assimilative capacity § 1.27(E)(2) of this Part will be considered a significant impact and will be required to demonstrate important economic or social benefits to justify the activity § 1.27(E)(5) of this Part.

e. Any proposed percent consumption of the remaining assimilative capacity may be deemed significant and invoke full requirements to demonstrate important economic or social benefits.

5. Demonstration that the discharge or activity is necessary to achieve important economic or social benefits to the State:

a. When the Department determines from BPJ and documentation provided by the applicant that a proposed new or increased discharge or activity would result in a significant impact to the existing water quality of a High Quality waterbody, the Department requires that the applicant demonstrate by a preponderance of clear and scientifically valid evidence having a probative value that the discharge or activity is necessary to achieve important economic or social benefits to the State. The applicant shall submit evidence to the Department, including but not limited to:

(1) Adequate scientific and technical evidence describing the magnitude and duration of the lowering of water quality.

(2) Adequate evidence detailing the extent of the important economic or social benefits that will accrue to the State from the proposed activity.

(3) Adequate scientific and technical evidence which demonstrates that the discharge or activity is necessary and methods of alternative production, alternative methods of treatment, or alternative sites for the activity will not achieve the important social or economic benefits.

b. Where RIDEM determines that the information/documentation provided by the applicant is insufficient to make a valid determination, the Department has authority to require additional information from the applicant before a decision is made.

c. Upon receipt and review of the applicant's antidegradation socioeconomic benefits demonstration, the Department may either determine that the significant change in water quality is not necessary to provide important economic or social benefit and deny the proposed new or increased discharge, or tentatively accept the demonstration and provide the opportunity for public comment on the action that may lower water quality in a high quality waterbody. The public participation requirement will be met by providing the public with the opportunity to comment and the opportunity to request a public hearing § 1.27(E)(6) of this Part.

6. Public Participation

a. When the Department determines that a proposed new or increased discharge or activity would result in either significant or insignificant impacts to the existing water quality of any High Quality waterbody, the Department will cause and approve public notice to be given by the applicant, in accordance with R.I. Gen. Laws Chapter 42-35, and said notice shall include:

(1) description of the proposed activity;

(2) Statement of the State's antidegradation policy and how the activity complies with the State's policy;

(3) A determination that existing uses will be maintained and protected;

(4) Summary of the expected water quality impact;

(5) Summary of the important economic or social benefits to the State.

(6) The notice shall invite written comments to be submitted to DEM, Water Resources, and shall provide an opportunity to request a public hearing.

b. For RIPDES permit related activities, this public notice may be a part of the normal public participation procedures involved with the issuance of a RIPDES permit.

c. Intergovernmental coordination and review will be fulfilled by submitting a copy of the public notice to the following agencies, requesting comment to be submitted to DEM, Water Resources by the public comment deadline.

d. State Agencies

(1) Governor's Policy Planning Office; RI Division of Statewide Planning, Department of Administration; RI Water Resources Board; RI Department of Economic Development; RI Office of Drinking Water Quality, Department of Health; RI Coastal Resources Management Council (as applicable).

e. Federal Agencies

(1) US EPA Region I; US Army Corps of Engineers; US Fish and Wildlife Service; National Marine Fisheries Service; National Park Service (as applicable).

(2) Once all public comment has been received (following the comment deadline), the Director of RIDEM or the Director's designee will respond to all significant comments. If significant evidence of need in terms of public interest, significant new technical information, or significant and valid disagreement as to technical conclusions exist, the Director or the Director's designee will hold a public hearing.

(3) Following this public participation process, the Director or the Director's designee will render a decision as to the allowance or denial for such activity to take place. If the application is denied, the applicant may revise the submittal to decrease or eliminate the projected impact to High Quality Waters, and resubmit the application for consideration under the full review process.

F. Antidegradation Protections for Tier 2 1/2 and Tier 3

1. Tier 2 1/2 - Protection of Water Quality for SRPWs

a. Special Resource Protection Waters (SRPWs) are a special subset of High Quality Waters. SRPWs are subject not only to Tier 2 protection but also special protection under Tier 2 1/2 of the Antidegradation Policy. Waterbodies which have been designated as SRPWs are listed in § 1.28 of this Part.

b. Under Tier 2 1/2, there shall be no measurable degradation of the existing water quality necessary to protect the characteristic(s) which cause the waterbody to be designated as a SRPW. The new or increased discharge or activity will not be allowed unless the applicant can provide adequate scientific and technical documentation and engineering plans which can prove, to the satisfaction of the Director, that specific pollution controls and/or other mitigation measures and BMPs will completely eliminate any measurable impacts to water quality necessary to protect the characteristics which cause the waterbody to be designated a SRPW.

c. If the RIDEM, using BPJ and scientific and technical knowledge of proper modern pollution control engineering practices, agrees that the specified pollution controls and/or BMPs will protect the SRPW from all measurable degradation, those agreed-to measures will be conditions required of the applicant in an approval. Any avoidance of such conditions by the applicant will result in automatic revocation of the approval and potential enforcement action. The burden of proof rests on the applicant.

d. Notwithstanding that all public drinking water supplies are SRPWs, public drinking water suppliers may undertake temporary and short term activities within the boundary perieter of a public drinking water supply impoundment for essential maintenance or to address emergency conditions in order to prevent adverse effects on public health or safety, provided that these activities comply with the requirements set forth in § 1.20(B) of this Part (Tier 1 Protection of Existing Uses) and § 1.20(C) of this Part (Tier 2 Protection of Water Quality in High Quality Waters).

2. Tier 3 - Protection of Water Quality for ONRWs

a. Outstanding National Resource Waters (ONRWs) are a special subset of High Quality Waters. ONRWs are subject not only to Tier 2 protection but also special protection under Tier 3 of the Antidegradation Policy.

b. Under Tier 3, the State cannot allow any degradation of the existing water quality necessary to protect and maintain ONRWs. There shall be no new or increased discharge to ONRWs or to tributaries to ONRWs that would result in lower water quality in the ONRW.

c. The State may allow some limited activities that result in temporary and short-term changes in the water quality of an ONRW. Such activities must not permanently degrade water quality or result in water quality lower than that necessary to protect the existing uses in the ONRW. During any period of time when, after opportunity for public participation in the decision, the State allows temporary degradation, all practical means of minimizing such degradation shall be implemented.

250 R.I. Code R. 250-RICR-150-05-1.27

Amended effective 12/28/2023