Rhode Island Code of Regulations › Title 250 - Department of Environmental Management › Chapter 150 - Water Resources › Subchapter 05 - Water Quality › Part 3 - Groundwater Quality Rules › Section 250-RICR-150-05-3.16 - Wellhead Protection

Current through June 14, 2024
A. Delineation of
				  Wellhead Protection Areas
1. Wellhead
				  protection areas for each public well in Rhode Island approved by the Rhode
				  Island Department of Health shall be established by the Department of
				  Environmental Management. A DEM approved wellhead protection area will be
				  effective at the time of the well's approval by the Rhode Island Department of
				  Health. See §
											3.24 of this Part for a
				  statewide map showing wellhead protection areas. Wellhead protection areas can
				  be viewed in greater detail on the DEM website at
www.dem.ri.gov
. Wellhead protection areas are
				  delineated in accordance with the following:
a. The wellhead protection area for community
				  and non-transient non community water supply wells completed in stratified
				  drift will be determined by DEM review of hydrogeologic models submitted by a
				  well owner. If such delineation is not available at the time of the well's
				  approval by the Department of Health, an interim wellhead protection area shall
				  be designated as a 2000 foot radius circle, until such time that a delineation
				  is accepted by the Department of Environmental Management.
b. The wellhead protection area for wells
				  completed in bedrock (community and non-community water supply wells) is a
				  calculated fixed radius based on the Rhode Island Department of Health approved
				  pump rate with a minimum radius of 1750 feet. See §
												3.16(A)(1)(b)(1)
				  of this Part for a list of pump rates and corresponding wellhead protection
				  area radii. For pumping rates not provided in §
												3.16(A)(1)(b)(1)
				  of this Part, the wellhead protection area radius shall be calculated using the
				  formula below in §
												3.16(A)(1)(b)(2)
				  of this Part.
(1) Wellhead Protection Area
				  Radius for Bedrock Wells
Pumping Rate
(gallons per minute)
Radius
(feet)
Pumping Rate
(gallons per minute)
Radius
(feet)
[GREATER THAN AND EQUALS TO]10
1750
23
2411
11
1820
24
2440
12
1872
25
2466
13
1920
30
2568
14
1965
35
2638
15
2008
40
2689
16
2087
45
2729
17
2153
50
2760
18
2211
60
2806
19
2261
70
2875
20
2305
80
2985
21
2344
90
3068
22
2380
100
3133
(2)
				  Where: s = drawdown (1 foot); Q = well pumping rate; T = transmissivity (374
				  gallons per day per ft); S = storage coefficient (.01 (dimensionless)); t =
				  time (200 days); W(u) = well function (dimensionless); and r = distance from
				  pumped well. 114.6 and 1.87 are coefficients generated for conversion from
				  metric to English units and conducting some simplifying calculations.
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c. The wellhead protection area for any other
				  groundwater source used as a public water system, including springs, wells
				  completed in till deposits, transient non-community water supply wells
				  completed in stratified drift, and any well where the geologic formation
				  supplying the water is unknown, will be a radius of 1750 feet.