Non-pressurized water filters and waste water purification installations relying only on a head or column of water in the filter to force the water through the filter for the treatment, purification, filtration, and supply of water and for the treatment of waste water, effluent, and sewage

Instrumentation and controls for the automatic monitoring and control of municipal water treatment systems, namely, software for monitoring and control of filter systems; mechanical, pneumatic and electronic control panels; electrical controllers for valve actuators; water flow meters; water turbidimeters; water pH meters; level transmitters; head loss transmitters; video monitors; computer printers; and replacement parts and components therefor