South Carolina Code of Regulations › Chapter 27 - CLEMSON UNIVERSITY STATE LIVESTOCK-POULTRY HEALTH COMMISSION › Article 17 - SOUTH CAROLINA PESTICIDE CONTROL › Section 27-1092 - Specifications and Records [pertaining to Backflow Prevention Act, Chemigation]

Current through Register Vol. 48, No. 6, June 28, 2024
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.