Chapter 18.21 AQUIFER PROTECTION OVERLAY DISTRICT
18.21.020 District boundaries.
18.21.050 Development standards.
18.21.060 Development plan review.
18.21.070 Major land development project approval – hydrogeologic evaluation.
A. The town of Richmond obtains all of its potable water from the Wood-Pawcatuck River basin watershed aquifer. The U.S. environmental protection agency has designated the aquifer as a sole-source aquifer, and the U.S. Congress has designated the Wood and Pawcatuck Rivers as wild and scenic rivers. The purpose of the aquifer protection overlay district is to protect the public health, safety and welfare by maintaining the quality of the groundwater that provides all of the town’s water supply.
B. The requirements applicable to the overlay district are in addition to those of the underlying zoning district. In the case of a conflict between the requirements of the overlay district and those of the underlying zoning district, the more restrictive requirements shall apply.
(Ord. dated 7-18-23)
18.21.020 District boundaries.
A. The boundaries of the aquifer protection overlay district are identical to those established by the R.I. department of environmental management to delineate the boundaries of the Pawcatuck basin aquifer, wellhead protection areas, and groundwater recharge areas.
B. Within the aquifer overlay protection district, there are two subdistricts that provide for different levels of groundwater protection:
1. The aquifer and all wellhead protection areas shall comprise subdistrict A.
2. The groundwater recharge areas shall comprise subdistrict B.
C. Uses permitted, allowed by special use permit, and prohibited in each subdistrict are shown in Chapter 18.16 of this Title.
D. The boundaries of the aquifer protection overlay district and its two subdistricts are shown on the official zoning map in the custody of the town clerk. The requirements of this Chapter apply only to the property included within those boundaries, regardless of the location of lot lines or zoning district lines, unless otherwise specifically provided.
(Ord. dated 7-18-23)
The following words have the following meaning when used in this Chapter.
Aquifer. A geologic formation, group of formations, or part of a formation that contains sufficient saturated, permeable material to yield significant quantities of water to wells and springs.
Containment area. A separate area with an impervious floor, covered by a roof, and surrounded on all sides by an impervious barrier intended to prevent substances from flowing in or out.
Groundwater. Underground water that completely fills the open spaces between particles of sand, gravel, clay, silt, and consolidated rock fractures.
Groundwater recharge area. The land surface from which water is added to the zone of saturation. The recharge area for a particular well or aquifer is that land surface from which water moves to the well or aquifer or may move to the well or aquifer under certain hydraulic
Hazardous material. A solid, semi-solid, liquid, or gaseous material that, because of its quantity, concentration, or physical or chemical characteristics, may cause or significantly contribute to an increase in mortality or an increase in serious irreversible or incapacitating reversible illness, or pose a substantial present or potential hazard to human health or the environment. Hazardous materials include materials defined as hazardous substances by the federal Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA), materials defined as hazardous waste by the department of environmental management rules and regulations for hazardous waste management (250-RICR-140-10-1), and petroleum products as defined by the department of environmental management rules and regulations for underground storage facilities used for regulated substances and hazardous materials (250-RICR-140-25-1). Hazardous materials include, but are not limited to, petroleum products, fertilizers, pesticides, and other substances in one or more of the following categories:
1. Ignitable. A gas, liquid or solid that may cause fire through friction or absorption of moisture, or a gas, liquid or solid that has a low flash point.
2. Carcinogenic. A gas, liquid, or solid that is considered by the U.S. environmental protection agency or the R.I. department of environmental management to cause cancer or genetic mutation.
3. Explosive. A reactive gas, liquid or solid that will react uncontrollably if exposed to heat, shock, pressure or any combinations thereof.
4. Toxic. A gas, liquid, or solid that endangers the life or health of any living thing coming into contact with it through a single exposure or repeated exposure.
5. Corrosive. An acid or alkaline material that will cause severe damage to human tissue or is capable of destroying containers of hazardous material and causing the release of their contents.
Wellhead protection area. The critical portion of a three-dimensional zone surrounding a public well or wellfield through which water will move toward and reach the well or wellfield.
Zone of saturation. The subsurface zone in which all open spaces are filled with water.
(Ord. dated 7-18-23)
A. No land shall be used and no structure shall be erected or renovated in the overlay district except in compliance with this Chapter.
B. Failure to maintain any use or structure in compliance with the requirements of this Chapter or in compliance with conditions imposed by the planning board or the zoning board of review shall be considered a violation of this Chapter.
(Ord. dated 7-18-23)
18.21.050 Development standards. All new structures in the overlay district, and all renovations of existing structures in the overlay district for which a building permit is required, shall comply with the following standards. All standards apply to the entire overlay district unless otherwise specified.
A. Sink drains. In any building where hazardous materials are likely to enter sinks, all sinks shall be directly connected to an above-ground holding tank separated from the onsite wastewater treatment system. The applicant shall submit details of the tank construction and conveyance system design, information about controls and alarm systems, and a service contract for pump-out and off-site disposal.
B. Floor drains. New structures shall be constructed with floor drains that empty into an above-ground holding tank separated from the onsite wastewater treatment system. The applicant shall submit details of the tank construction and conveyance system design, information about controls and alarm systems, and a service contract for pump-out and off-site disposal.
C. Indoor storage of hazardous materials. Every indoor area where hazardous materials will be stored shall be enclosed by a secondary containment system with a capacity of 110% of the volume of material in the storage area.
D. Outdoor storage of hazardous materials. Every outdoor area where hazardous materials will be stored shall have a roof, shall be enclosed on three sides, and shall be constructed to prevent precipitation from flowing into the area. If the area will be used to store liquid materials, the area shall be designed to hold 110% of the liquid stored inside it.
E. Loading areas. All loading areas where hazardous materials will be handled shall be enclosed by a roof and two sides to prevent precipitation from entering the area.
F. Dumpsters. Dumpsters shall have drain plugs intact and shall be covered or located under a roof.
G. Exterior catch basins. All exterior catch basins, trench drains, and other conveyance systems for collecting and managing stormwater shall be equipped with sumps and water quality hoods to prevent discharge of spilled oil or petroleum products.
H. Above-ground storage tanks. Every interior and exterior above-ground storage tank for fuel or heating oil, except those in single-family and two-family residential structures, shall include a secondary containment system with a capacity that is 110% of the tank volume. The system shall include a dedicated basin, tub or tray specifically manufactured for use as a secondary containment area for petroleum products.
I. Underground storage tanks. Installation of new underground storage tanks for hazardous materials is prohibited.
(Ord. dated 7-18-23)
18.21.060 Development plan review.
The purpose of development plan review of uses in the aquifer overlay protection district is to ensure that all changes in the nature and intensity of land use are designed and constructed in a way that will minimize impact on the aquifer.
A. Development plan review pursuant to Chapter 18.54 of this Title is required for:
1. Development of all new principal uses and accessory uses that are permitted by right, except single-family and two-family structures.
2. Construction of all new structures that are permitted by right, except single-family and two-family structures and structures in major land development projects.
3. All changes of use from one use code to another.
B. Advisory development plan review is required for all special permit uses, including special use permits for enlargement, expansion, or intensification of a legal nonconforming use. The zoning board of review shall not open a public hearing on a special use permit application until the planning board’s advisory development plan review decision has been issued.
C. The following information shall be submitted with a development plan review application:
1. The name and quantity of every hazardous material that will be used or stored on the premises, the location where it will be used or stored, and a material safety data sheet for each hazardous substance.
2. For all buildings and uses where hazardous materials will be used or stored, a spill prevention plan and a hazardous waste contingency plan that complies with the department of environmental management rules and regulations for hazardous waste management (250-RICR-140-10-1).
3. Proposed water source and estimated volume of water use, including fire protection flow demands.
4. Documents illustrating how the proposed use or uses and structure or structures will comply with the requirements of this Chapter.
D. The planning board shall have the authority to require an applicant for development plan review to submit a nitrate loading analysis to evaluate the potential impacts on the parcel and surrounding parcels if there is a reasonable basis to believe that past uses, current uses, or proposed uses of the property could significantly increase the nitrate level of the groundwater. The analysis should compare the existing and proposed nitrate load concentrations to the maximum contaminant level of 10 milligrams per liter (10 mg/L) established by the U.S. environmental protection agency. The analysis shall be submitted after a pre-application conference and shall be peer-reviewed before development plan review takes place.
E. Conditions of approval.
1. The planning board shall have the authority to impose conditions on development plan approval that are intended to maintain groundwater quality and to minimize groundwater withdrawal. The conditions shall be based on competent evidence in the record, and the planning board shall make findings of fact to support the imposition of conditions.
2. For advisory development plan review, the planning board shall have the authority to recommend to the zoning board of review conditions on approval that are intended to maintain groundwater quality and to minimize groundwater withdrawal. The conditions shall be based on competent evidence in the record, and the planning board shall include in its recommendation findings of fact to support the recommended conditions.
F. The administrative officer shall have the authority to review and approve applications for development plan review that involve only changes in use code or minor alterations to existing structures. The applicant shall have the right to request planning board review of any conditions imposed by the administrative officer on administrative development plan approval.
G. The planning board shall have the authority to require peer review of any technical submission. The applicant shall bear the cost of such review. The administrative officer shall obtain an estimate of the cost of the review and the applicant shall pay a project review fee adequate to cover the estimated cost. Section 11.3.2 of the land development and subdivision regulations shall govern the manner in which the fees are collected and refunded and the applicant’s right to request an account balance or request a different peer reviewer.
(Ord. dated 7-18-23)
18.21.070 Major land development project approval – hazardous materials.
A. For every major land development project that includes buildings or uses where hazardous materials will be used or stored, the following information shall be provided with the Master Plan submission:
1. The name and maximum quantity of every hazardous material that will be used or stored on the premises and the location where it will be used or stored.
2. A spill prevention plan and a hazardous waste contingency plan that complies with the department of environmental management rules and regulations for hazardous waste management (250-RICR-140-10-1).
The planning board shall have the authority to impose conditions on approval that are intended to prevent groundwater contamination.
(Ord. dated 7-18-23)
18.21.080 Major land development project approval -- hydrogeologic evaluation.
A. At Master Plan submission, the applicant shall submit a preliminary hydrogeologic evaluation of the property to determine whether any conditions are present that would affect the quality of the groundwater, based on observation and examination of available public data, and to determine how the proposed development will affect the quality and quantity of the groundwater.
B. The preliminary hydrogeologic evaluation shall be prepared by a registered professional engineer with advanced training in hydrogeology.
C. The preliminary hydrogeologic evaluation should include:
1. A site visit to observe the general condition of the property and surrounding properties, including use of the property, topography, utilities, bedrock outcrops, and wetlands and water bodies.
2. Examination of public records including historical aerial photographs and records of existing septic systems and wells.
3. Determination of the current and past uses of the property and whether there are any known concerns about water quality or quantity or past contamination.
4. A geological assessment including groundwater classification, groundwater flow direction, contributing watersheds, bedrock, soil types, and soil strata, thickness, and composition.
5. A description of the surface water and watershed characteristics.
6. Test pit and percolation test results, with a site plan showing the test locations.
7. A nitrate loading analysis to evaluate the potential impacts on the parcel and surrounding parcels. The analysis should compare the existing and proposed nitrate load concentrations to the maximum contaminant level of 10 milligrams per liter (10 mg/L) established by the U.S. environmental protection agency.
8. The Site Context Plan, Existing Conditions and Resources Plan, and Development Overlay Plan submitted with the Master Plan application, supplemented as necessary to show hydrogeologic features.
D. A peer-reviewed preliminary hydrogeologic evaluation shall remain valid for the purpose of land development project approval unless there is a substantial change in conditions at or near the site that could affect groundwater quality, including but not limited to new construction, installation of onsite wastewater treatment systems or wells, or hazardous material spills or other environmental events that could affect soil or groundwater.
E. If the proposed development projects maximum daily groundwater use of 4,600 gallons a day or greater, if wells will be closer than 200 feet to each other, if industrial development is proposed, or if the Planning Board finds, based on the peer review of the preliminary hydrogeologic evaluation, that the proposed development could have a significant impact on the quality or quantity of the groundwater at the property or adjacent properties, the applicant shall carry out a well field test. The purpose of the well field test is to conduct pumping tests to determine available yield and groundwater flow direction, and to demonstrate that wells on the property will produce potable water. Pumping test data must be plotted, interpreted, and analyzed. The method of analysis and the resulting aquifer properties, including well yield, specific capacity, transmissivity, and storage, must be described. The analysis shall be submitted with the Preliminary Plan application.
F. The following requirements apply to well field tests:
1. Test wells shall be drilled bedrock wells unless overburden wells are planned for the proposed development.
2. For residential development, two wells are required for five to ten units, three wells are required for eleven to twenty-four units, four wells are required for twenty-five to fifty units, five wells are required for fifty-one to seventy-five units, and six wells are required for seventy-six to one hundred units.
3. For residential development, the test well should be located throughout the property in a way that will accurately reflect the hydrogeologic conditions throughout the site. For commercial or industrial development, the test well shall be located at the proposed location of the water supply well. Wells must be located so that well water is discharged a sufficient distance away from other test wells to prevent inaccurate readings.
4. Construction of test wells must comply with applicable State regulations and must be supervised by a qualified engineer, geologist or hydrologist who will record detailed site geology information during installation.
5. Pumping tests should be carried out at all test wells. Before pumping tests take place, wells should be free of sand and mud. Discharge water should be checked periodically for sediment during the test. Excessive sediment indicates that the well needs additional development.
6. Initial step drawdown pumping tests appropriate for the proposed use should be performed in all test wells to estimate well yields and to determine the optimum rate for a constant rate pumping test. The step drawdown pumping tests should include a minimum of four pumping intervals consisting of a minimum period of thirty minutes each. The constant rate pumping tests should begin with a static water level and should be performed at a fixed pumping rate (plus or minus 5%) for a minimum of eight hours for residential development, and forty-eight hours for commercial or industrial development.
7. Before a constant rate pumping test, test wells should be sufficiently recovered. When a constant rate pumping test is taking place on one well, other test wells should be used as observation wells, with drawdown and recovery times recorded. A pumping test should include regular water level measurements during and after pumping until 95% recovery occurs, or until sufficient data have been collected to establish a recovery curve. Water levels should be continuously monitored at an appropriate frequency in pumping wells and observation wells.
8. Water level should be measured in feet and hundredths of a foot. The flow rate during the pump test should be measured using a flow meter and flow totalizer. Flow rate readings should be documented every hour and confirmed with a 5-gallon bucket and stopwatch.
9. A water sample should be collected at the end of the pump test. Water quality testing must comply with approved U.S. environmental protection agency methods. Samples must be analyzed by a State certified laboratory for the substances listed below, and for any other substances the planning board has reason to believe might be present.
i. Total dissolved solids
l. Total coliform bacteria
o. E. coli bacteria
u. Volatile organic compounds (VOCs)
v. Methyl tert-butyl ether (MTBE)
10. If a well is drilled into bedrock, gross alpha screen and radon testing shall be performed. If the gross alpha screen detects radiation of 15 or more picocuries per liter of air (pCi/L), the water must be analyzed for radium and uranium concentrations.
11. After field testing is complete, test wells that will not be used for water supply or long-term monitoring must be decommissioned.
F. The planning board shall have the authority to impose conditions on approval that are intended to maintain groundwater quality and to minimize groundwater withdrawal. The planning board shall make findings of fact to support the imposition of any condition.
(Ord. dated 7-18-23)
Title 46, chapter 13.1 of the general laws; R.I. Gen. Laws § 45-24-30(3)(i), § 45-24-30(4); § 45-24-33(a)(7), (20).
250-RICR-150-05-3 - DEM Groundwater Quality Rules.
250-RICR-150-10-6 - DEM Rules Establishing Minimum Standards Relating to Location, Design, Construction and Maintenance of Onsite Wastewater Treatment Systems.
250-RICR-140-25-1 - DEM Rules and Regulations for Underground Storage Facilities Used for Regulated Substances and Hazardous Materials.
250-RICR-140-10-1 - DEM Rules and Regulations for Hazardous Waste Management.