Plan Review for Chemical Feed Systems

What do I need to include in a submittal of chemical feed system plans and specifications?

• Manufacturer name and product name for each chemical.  All chemicals must be ANSI/NSF Standard 60 certified and listed.
• Safety Data Sheet (SDS) for each chemical.
• Descriptions of all feed and storage equipment, including maximum and minimum feed ranges.
• Location of feeders, piping layout and points of application on a scaled floor plan of the facility.
• Descriptions and locations of storage and handling facilities.
• Written operating and control procedures including proposed application rates.
• Descriptions of testing equipment.
• System diagrams showing all tanks with capacities, (with drains, overflows, and vents), feeders, transfer pumps, connecting piping, valves, points of application, backflow prevention devices, and air gaps.
• Descriptions and locations of secondary containment systems, and safety eye washes and showers.
• Purpose of the chemical.
• Chemical use label.

What are the requirements for installing a gas chlorine system?

• Gas chlorine must be fed using a vacuum system.  Pressurized feed of gas chlorine is not acceptable.
• The gas chlorine equipment must be enclosed and separated from other operating areas.
• The gas chlorine room must be equipped with a ventilation system that provides at least one air exchange per minute. The intake for the exhaust fan shall be located near the floor, and the fresh air intake shall be located near the ceiling.
• The chlorine room doors must be equipped with panic hardware, open outward, and provided with a “Danger: Chlorine Gas” sign.
• A shatter-resistant inspection window must be installed in an interior wall of the gas chlorine room.
• Separate switches shall be located outside the gas chlorine room doors and at the inspection window for the chlorine room fan and lights.  Outside switches should be protected from vandalism and have a signal light indicating fan operation.
• Pressure relief valves for the chlorine regulators must be vented to the outside atmosphere and screened.
• All chlorine cylinders must be properly restrained to prevent upset.
• A continuous electronic chlorine leak detector should be installed that is equipped with both an audible alarm and a warning light.
• Floor drains are not recommended to be installed in gas chlorine rooms.  If floor drains are installed, they shall discharge to the outside of the building, and shall not be connected to any other internal or external drainage systems.

Where on the process piping does the chemical feed point need to be located?

The chemical injector must connect to the lower half of the pipe.

Chemical Storage Guidance:

All new water treatment facilities shall store incompatible chemicals in separate rooms according to the Environmental Protection Agency guidance for Incompatible Chemical Storage (PDF). Rehabilitated water treatment facilities should attempt to separate incompatible chemicals as much as possible and provide separate secondary containment at a minimum.