S.C. Code Regs. § 27-1092 - Specifications and Records [pertaining to Backflow Prevention Act, Chemigation]

A. The anti-siphon devices required by these regulations and the act to be installed: check valve, vacuum breaker, low pressure drain, and mechanical or electrical interlock, cannot be altered in any way that negates their effectiveness. They must be constructed of materials resistant to chemicals and maintained functionally free of corrosion or other build up and must remain operative at all times when chemigating.

B. The low pressure drain and the vacuum breaker must be placed upstream, oriented by the direction of water flow, from the check valve. Therefore, the low pressure drain and the vacuum breaker must be placed between the check valve and the water source. The relative position of the vacuum breaker and the low pressure drain to each other is unimportant.

C. Regulatory Programs must be notified of any actual or suspected contamination of the water source resulting from chemigation.

D. Records of chemigation applications shall be maintained for a period of two years, and must be shown to Regulatory Programs agent upon request. These records will include: type chemical applied, date, rate of chemical applied, site, and water source. These records can be met as notations on the chemical purchase invoice or production logs.

E. All chemical label requirements for chemigation must be followed when chemigating.

F. The low pressure drain should be connected to a hose or pipe which will prevent contaminated water from draining into the water source. The outlet of this drain system must be at least 20 feet from the water source. The low pressure drain outlet on the irrigation pipe line should be at least two inches above grade, to facilitate connecting the drain line. The low pressure drain must be constructed so that the top of the drain is flush with the bottom of the irrigation pipe to properly drain all contaminated water in the irrigation pipe.

G. Check valves must be positive closing. They must be flanged and bolted onto the irrigation pipe or otherwise constructed in order that they can be removed for servicing; welded in check valves which cannot be removed for inspection and servicing are not permitted. Maintenance shall be as necessary to insure proper performance of the check valve. The Regulatory Programs agent determination of the need for replacement of the seals, discs, or other portion of the check valve prone to maintenance will be final and adhered to by the chemigator, or the equipment will be considered ineffective and in violation of the act.

H. Where chemigation is accomplished by gravity flow or venturi systems, one of the following must be accomplished to prevent continued chemigation should the system shut down:

(1) Check valve that requires positive head for opening at least 10 psi cracking pressure should be installed on the chemical supply line on the discharge side of the chemical injection pump such that the valve opens only when the irrigation line is adequately pressurized. When head is lost on the irrigation pipe this check valve will shut preventing further passage of chemicals. The chemical pump, if operating this device must be installed.

(2) An automatic operated valve installed on the chemical supply line on the intake side of the chemical injection pump. This valve must open only when the irrigation line is adequately pressurized; it must prevent leakage from the chemical supply tank upon system shutdown. If the valve is electrical and power is lost at the irrigation pump, it must be shut down preventing further passage of chemicals.

(3) An elevated loop of the chemigation pipe must be installed between the irrigation pipe and the chemigation tank such that the top of the loop is higher than the top of the chemigation tank. A vacuum relief valve must be installed at the top of this loop which would prevent flow of materials in either direction should the venturi draw on the chemigation tank be stopped.

Notes

S.C. Code Regs. § 27-1092

Added by State Register Volume 15, Issue No. 4, eff April 26, 1991.

Statutory Authority: 1976 Code Section 46-1-140