3.2 Public Water Supply Setbacks & Special Permits (Pes 502.03-502.05)

3.2 Public Water Supply Setbacks & Special Permits (Pes 502.03-502.05)

The New Hampshire Department of Environmental Services reports that roughly 46 percent of state residents draw their drinking water from private wells, and the state's public systems draw from surface reservoirs and from highly permeable stratified-drift aquifers. The state's response is a small set of specific, memorizable distances. Get these exactly right; approximations lose points and, in the field, lose licenses.

---

The three numbers

+------------------------------------------------------------------+
|  NEW HAMPSHIRE PUBLIC WATER SUPPLY SETBACKS                      |
+------------------------------------------------------------------+
|  400 FEET   from GRAVEL PACKED wells used for public water       |
|             supply                                     Pes 502.05 |
|  250 FEET   from OTHER wells used for public water supply         |
|                                                        Pes 502.05 |
|  250 FEET   from the REFERENCE LINES of surface waters or their   |
|             tributaries used for public water supply, for a       |
|             radial distance of 5 MILES from the intake            |
|                                                        Pes 502.04 |
+------------------------------------------------------------------+
|  Each may be waived ONLY by a Division special permit issued      |
|  upon consultation with the DES water division.                   |
+------------------------------------------------------------------+

The direction of the pair is the trap. Gravel packed public supply wells get the LARGER setback (400 feet), because a gravel-packed well is screened in permeable stratified drift and draws a wide, fast cone of influence. Other public supply wells - including bedrock wells - get 250 feet. If a question reverses those numbers, it is wrong.

Pes 502.05, verbatim in substance

No pesticide application shall be made within 400 feet of gravel packed wells used for public water supply or within 250 feet of other wells so used, unless materials and methods to be employed have been approved through the issuance of a special permit according to the procedures of Pes 502.04, by the division upon consultation with the water division, department of environmental services.

Note what the rule does not say. It sets no statewide setback from private drinking water wells for ordinary application. Private wells are addressed in the mixing and loading rules instead: Pes 805.01(c) forbids mixing or loading within 75 feet of surface water or private water wells, and Pes 502.06(f)(6) applies the same 75 feet to chemigation pesticide containers.

---

Pes 502.04 - applications within public water supply watersheds

Applications within 250 feet of the reference lines of surface waters or their tributaries used for public water supply, anywhere within a 5-mile radial distance measured from the public water supply intake inside that watershed, require a special permit issued after consultation with the DES water division.

The permit application (Form SP-PW)

The applicant supplies:

• name, address, telephone, and registration number of the applicator;
• name, address, and telephone of the person requesting the application;
• a description of the application: target organism, method, pesticides, rate, number of applications and approximate treatment dates;
• a description of the property: number of blocks and acreage of each, and an outline of all activities in the treatment area that might be affected;
• the name, PWS identification number assigned by DES, and location of any public water supply intakes within 5 miles downstream;
• the reason or need for the application;
• except during a public health emergency, a statement that property owner approval has been obtained;
• an acknowledgment that falsification results in denial; and
• date and signature.

The applicant also attaches complete labels of the pesticides and a detailed scale map showing treatment areas, adjacent areas, surface waters, topographic features, and land types.

The Division acts under RSA 541-A:29, using the criteria in Pes 603.02(a) and (b), and issues a written permit stating the terms of approval, or a written denial stating reasons.

The 5-day contamination report

Pes 502.04(i) is easy to overlook and easy to test:

Any pesticide applicator having knowledge or reason to believe that contamination of surface waters or their tributaries used for public water supply has occurred shall immediately report verbally and in writing within 5 days of such contamination to the division of pesticide control.

The standard is knowledge or reason to believe, not proof.

---

Pes 502.03 - waterfront buffers and wetlands

This rule is narrower than candidates assume. It applies to applications in a waterfront buffer, in the buffer of surface waters not covered by RSA 483-B, or to a wetland, for the control of forest insects, mosquitoes, black flies, or other biting arthropods. Those applications require a special permit issued by the Division on Form SP-WB.

Three definitions the rule supplies for itself:

The SP-WB application is detailed: survey data and public-health-threat information justifying treatment, target organisms, application methods, method and frequency of calibration of equipment used, pesticides, schedule and acreage, environmental considerations including a justification for using any pesticide whose label carries groundwater, surface water, pollinator, or aquatic precautions, and a list of any potentially affected endangered species. Where the treatment area is a wetland, the applicant states whether the wetland is under 10 acres, whether one owner controls the entire wetland and shoreline, whether co-owners agree, and whether there is a regularly flowing outflow and how it will be controlled.

---

Putting the water rules together

---

Worked example

A Category B applicator is scheduled to treat brush along a town road. The route passes a municipal gravel packed wellfield, crosses a tributary that feeds a reservoir whose intake is about three miles downstream, and runs within 30 feet of a small unnamed brook that is not a protected shoreland under RSA 483-B.

• Within 400 feet of the gravel packed public supply well, no application may be made without a Pes 502.05 special permit.
• Along the tributary of a public supply surface water within 5 miles of the intake, no application may be made within 250 feet of the reference line without a Pes 502.04 special permit obtained in consultation with DES.
• Along the unnamed brook, Pes 1001.01 prohibits application within 25 feet of the reference line, and also prohibits applying beyond 25 feet in a manner that would put pesticide inside that 25 feet.
• The right-of-way work itself already requires a Pes 505.02 special permit on Form ROW/WL.
• If the crew later learns that spray reached the tributary, the applicator must report verbally immediately and in writing within 5 days.