250 R.I. Code R. 250-RICR-150-05-3.12

Current through November 7, 2024

Section 250-RICR-150-05-3.12 - Determination of Compliance with Groundwater Quality Standards and Preventive Action Limits

A. Compliance with the groundwater quality standards and preventive action limits shall be determined through analytical tests of unfiltered groundwater samples. Groundwater quality samples shall be collected in a manner to be representative of groundwater quality.

B. Groundwater Monitoring

1. All facilities that are required by the Director to monitor groundwater quality pursuant to these Rules shall implement a groundwater monitoring plan approved by the Director. Groundwater monitoring plans approved pursuant to other Rhode Island Department of Environmental Management Rules and Regulations shall be exempt from this requirement.

2. The groundwater monitoring plan shall include, at minimum, the following:

a. A locus map using the U.S. Geological Survey 7.5 minute quadrangle map;

b. Site plan at an appropriate scale (minimum scale of 1 inch equals fifty feet (1"=50')) to adequately show the monitoring well locations, well casing elevations, and the location on and immediately surrounding the site of the following: property boundaries, buildings and other structures, roads, surface topography, watercourses, wells, water lines, sewer lines, onsite wastewater treatment systems and other waste disposal areas, and any other significant site features;

c. A sufficient number of wells (minimum of 3) at the appropriate locations and depths to permit detection of any pollutants in the groundwater;

d. Well logs with detailed lithologic and well construction information; and

e. Sampling schedule.

3. Monitoring well construction shall be in compliance with the standards set forth in § 3.22 of this Part.

4. Minimum site monitoring requirements:

a. The static water table elevation shall be recorded at the time of monitoring; and

b. A log containing static water table elevations and the sample analyses shall be maintained on-site by the facility owner or operator.

5. Copies of sample results and water table measurements shall be submitted to the Director within 30 days of the receipt of such information by the facility owner or operator.

6. An approved groundwater monitoring plan shall be valid for a duration specified by the Director.

7. There shall be no change in a groundwater monitoring plan without the approval of the Director. The Director may require a change in an approved monitoring plan where such change is necessary to determine compliance with the groundwater quality standards.

8. Any person transferring ownership or control of a facility having an approved groundwater monitoring plan shall notify the Director of such transfer not less than 30 days prior to the effective date of such transfer.

9. Groundwater monitoring required by the Director shall not be terminated without the approval of the Director.

10. When groundwater monitoring has been terminated, the monitoring wells shall be abandoned in accordance with the procedures established in § 3.22 of this Part.

C. Points of compliance with the groundwater quality standards and preventive action limits must be approved by the Director. The Director may designate any point where groundwater is withdrawn for use or monitored as a point of compliance. Points of compliance shall be within the area of known or suspected groundwater pollution unless a pollutant discharge zone or residual zone is designated pursuant to §§ 3.12(D) and (E) of this Part, respectively. If a pollutant discharge zone or residual zone is designated, the points of compliance shall be at the boundary of such zone.

D. Pollutant Discharge Zone: In determining compliance with the groundwater quality standards and preventive action limits in these rules for a discharge to groundwater where the groundwater is classified GAA or GA, the Director may approve, deny, or modify a pollutant discharge zone proposed by a facility owner or operator. Within this pollutant discharge zone, the pollutant concentrations in groundwater are allowed to be greater than the groundwater quality standards.

1. The facility owner or operator proposing a pollutant discharge zone shall provide the Director with sufficient information on the site's hydrogeology and the characteristics of the discharge to groundwater to support the proposed pollutant discharge zone delineation.

2. A groundwater monitoring plan shall be submitted to the Director at the same time that a pollutant discharge zone is proposed, unless the Director determines that groundwater monitoring is not necessary.

3. Prior to approval of a pollutant discharge zone, the facility owner or operator shall demonstrate by clear, convincing, and scientifically valid evidence that:

a. All practical alternatives to a discharge to groundwater have been evaluated and no technically or economically feasible alternative exists;

b. Every practical effort has been made to limit the pollutant concentrations in the discharge to groundwater by such means as, but not limited to, reducing the quantity of potentially contaminating substances in use, use of alternative substances, changes in the operational procedures at the facility, and pretreatment of the effluent;

c. The pollutant discharge zone is limited to the smallest area that is technically and economically feasible;

d. The facility owner or operator has acquired rights to the pollutant discharge zone as evidenced by ownership of the land within the pollutant discharge zone, ownership of an easement to such land, or otherwise controls such land to the Director's satisfaction. Any such easement or other control mechanism shall prohibit use of the groundwater for a drinking water supply and provide the right to enter the pollutant discharge zone for groundwater monitoring and, if necessary, remediation activities.

e. The discharge to groundwater and the resulting groundwater quality in the pollutant discharge zone do not represent a threat to public health or the environment;

f. There will be no violation of the groundwater quality standards established in § 3.11 of this Part beyond the pollutant discharge zone as a result of the proposed discharge;

g. There will be no adverse impact on existing public or private wells as a result of the proposed discharge; and

h. The groundwater within the pollutant discharge zone will not cause a violation of the surface water quality standards established by the Rhode Island Water Quality Regulations Part 1 of this Subchapter as a result of the proposed discharge.

4. For a discharge to groundwater from an onsite wastewater discharge system permitted pursuant to the Rhode Island Rules Establishing Minimum Standards Relating to Location, Design, Construction and Maintenance of Onsite Wastewater Treatment Systems, Subchapter 10 Part 6 of this Chapter, the pollutant discharge zone shall be defined by the separation distance required in those rules between the edge of the leachfield and a private well.

5. For a discharge to groundwater from a stormwater treatment system permitted pursuant to the Rhode Island Stormwater Design and Installation Rules, Subchapter 10 Part 8 of this Chapter, the pollutant discharge zone shall be defined by the separation distances required in the Manual between the edge of a stormwater treatment system and a private well.

E. Residual Zone: In determining compliance with the groundwater quality standards in these rules for groundwater remediation activities where the groundwater is classified GAA or GA, the Director may designate or approve, deny, or modify the designation of a residual zone proposed by the facility owner or operator.

1. Within this residual zone, the pollutant concentrations in groundwater are allowed to be greater than the groundwater quality standards. The Director may require that the groundwater quality within the residual zone be monitored.

2. Prior to approval of a residual zone, the facility owner or operator shall demonstrate by clear, convincing and scientifically valid evidence that:

a. The source of the pollutants has been removed or controlled to the satisfaction of the Director and every practical effort has been made to decrease the pollutant concentrations in the residual zone;

b. The residual zone is limited to the smallest area that is technically and economically feasible;

c. The facility owner or operator has acquired rights to the residual zone as evidenced by ownership of the land within the residual zone, ownership of an easement to such land, or otherwise controls such land to the Director's satisfaction. Any such easement or other control mechanism shall prohibit use of the groundwater for a drinking water supply and provide the right to enter the residual zone for groundwater monitoring and remediation activities;

d. The pollutant concentrations in the groundwater within the residual zone do not or will not represent a threat to the public health or the environment;

e. There will be no adverse impact on existing public or private wells as a result of the residual zone;

f. There will be no violation of the groundwater quality standards established in § 3.11 of this Part beyond the residual zone; and

g. The groundwater within the residual zone will not cause a violation of the surface water quality standards established by the Rhode Island Water Quality Regulations, Part 1 of this Subchapter.

250 R.I. Code R. 250-RICR-150-05-3.12

Adopted effective 1/9/2019
Amended effective 12/28/2023