Wisconsin Administrative Code
Department of Natural Resources
NR 800 - Environmental Protection - Water Supply
Chapter NR 812 - Well Construction And Pump Installation
Subchapter III - Requirements for New Pump Installations and Water Treatment
Section NR 812.38 - Injection of fertilizers or pesticides for agricultural purposes

Universal Citation: WI Admin Code ยง NR 812.38

Current through August 26, 2024

(1) POTABLE WATER SUPPLIES OR SYSTEMS. Chemical addition to a potable well or water system may only be undertaken according to the requirements of s. NR 812.37. The injection of fertilizers or pesticides into a potable well or water system is prohibited. No person may inject fertilizers or pesticides into a potable well or water system. Fertilizers or pesticides may be used with potable water systems by repumping from a tank or a pond. The discharge from the well pump into a reservoir or pond shall have a free fall from a point at least 2 feet above the established reservoir or pond overflow elevation.

(2) NONPOTABLE WATER SUPPLIES.

(a) Injection of fertilizers.
1. The injection of fertilizers into a nonpotable well, well pump suction pipe, or pump column is prohibited. No person may inject fertilizers into a nonpotable well, well pump suction pipe, or pump column.

2. Fertilizer may be injected in the discharge pipe of a booster pump delivering water from a tank or sealed pond into which the well pump discharges through an air gap from a point at least 2 discharge pipe diameters above the overflow level of the tank or pond.

3. Fertilizer may be injected into the well pump discharge pipe of a nonpotable water system if it is injected with a positive displacement type chemical feed pump or other approved equipment at a point downstream of a reduced pressure principle backflow preventer which complies with ch. SPS 384 and is installed in accordance with ch. SPS 382 or downstream of an UL approved check valve installed in the well pump discharge pipe at the well site. The chemical feed pump shall be shut off at least 10 minutes prior to shutting off of the well pump so as to purge the chemical from the water system.

4. Fertilizer may be introduced into the well pump discharge pipe of a nonpotable water system if it is aspirated into the well pump discharge pipe with a venturi-type aspirator and the injection point is downstream of a barometric pipe loop extending at least 35 feet above the highest part of the downstream discharge piping.

(b) Injection of pesticides.
1. The injection of pesticides into a nonpotable well, well pump suction pipe, or pump column is prohibited. No person may inject pesticides into a nonpotable well, well pump suction pipe, or pump column.

2. Pesticide may be injected in the discharge pipe of a booster pump delivering water from a tank or pond into which the well pump discharges through an air gap from a point at least 2 discharge pipe diameters above the overflow level of the tank or pond.

3. Pesticide may be injected into the well pump discharge pipe of a nonpotable water system if it is injected with a positive displacement type chemical feed pump or other approved equipment at a point downstream of a reduced pressure principle backflow preventer, which complies with ch. SPS 384 and is installed in the well pump discharge pipe at the well site but subject to the following conditions:
a. The department shall be notified by the owner of the nonpotable water system of when and where a reduced pressure principle backflow preventer is installed in a system and when it is removed,

b. The reduced pressure principle backflow preventer shall be installed and maintained in accordance with ch. SPS 382,

c. The reduced pressure principle backflow preventer shall be installed above the regional flood level and the location shall be accessible for testing, inspection and maintenance,

d. The reduced pressure principle backflow preventer may not be bypassed or made inoperative nor removed from an irrigation system in which pesticides continue to be injected into the well pump discharge pipe,

e. Annual testing of the reduced pressure principle backflow preventer shall be conducted with a differential pressure gauge in accordance with the ASSE Standard 1013 testing method for reduced pressure principle backflow preventers by a DSPS listed backflow prevention device tester, and the owner of the system shall send a report of the test results to DSPS at least once each year, and

f. Pesticide application and use in compliance with this section shall conform to ch. ATCP 29.

Note: Lists of DSPS approved reduced principle backflow preventers are available from DSPS. Listing as a tester of reduced pressure principle backflow preventers may be obtained following successful completion of a training course accepted by DSPS. Lists of testers willing to perform the required testing are available from DSPS.

4. Pesticide may be introduced into the well pump discharge pipe of a nonpotable water system if it is aspirated into the well pump discharge pipe with a venturi-type aspirator and the injection point is downstream of a barometric pipe loop extending at least 35 feet above the highest part of the downstream discharge piping.

Disclaimer: These regulations may not be the most recent version. Wisconsin may have more current or accurate information. We make no warranties or guarantees about the accuracy, completeness, or adequacy of the information contained on this site or the information linked to on the state site. Please check official sources.
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