Texas Waste Water Treatment Ch#14 Records and Safety Practices

Plant records should include the following general information: • Temperatures (air, wastewater, sludge) • Rainfall • Wind direction • Meter readings • Sludge handling (raw and digested) • Screening and grit records • Laboratory results, both plant and sludge analysis • Process control results • Operators’ daily logs • Irrigation records (if applicable)

To be of value, laboratory test results must be permanently recorded.

The TCEQ monthly effluent report must be submitted to the TCEQ in Austin by the 20th day of the month following the month being reported.

In the raw waste part of the plant, flammable liquids, such as greases, oils, gasoline, and other petroleum products, present a serious danger. So do toxic substances, such as >acids<, >caustics<, insecticides, >chemical fertilizers<, and cleaning compounds. These substances should not be dumped into the collection system. They will kill the bacteria necessary for wastewater treatment. However, hazardous substances are still found in the system.

All digester roofs or covers should be equipped with pressure relief, vacuum relief, and flame-trap valves. A waste-gas flame stack with a manually operated positive drip trap should be connected to the gas dome. No smoking or other combustion can be permitted on the roof or around the gas dome.

During wastewater decomposition, various hazardous gases form in the collection system and in the wastewater plant. They fall into three general classifications: • Combustibles and explosive gases • Asphyxiation-producing gases • Poisonous or toxic gases

Hydrogen sulfide, a product of organic decay in wastewater, is heavier than air, colorless, and flammable. In small concentrations it has a rotten-egg odor. Exposure for two to fifteen minutes at 0.01% impairs the sense of smell. Exposure to amounts of 0.07%–0.1% rapidly causes acute poisoning, paralyzing the lungs.

Methane is a colorless, odorless, tasteless, and highly flammable gas that deprives body tissues of oxygen and will not support life. Methane constitutes about 65%–75% of digester gas and is explosive at a 5%–15% concentration.

Chlorine is a heavy, non-combustible, greenish-yellow gas with a pungent, irritating odor and very low electrical conductivity. It is highly toxic as an inhalant and a moderate fire risk in contact with turpentine, ether, ammonia, hydrocarbons, hydrogen, powdered metals, or reducing materials.

No skin break is too small for infection to enter. Skin infections and injuries may be caused by chemicals, insect bites, abrasions, and extreme heat or cold. Cleanliness is the best protection against infection and disease. Even very minor injuries require immediate cleaning and treatment. Washing and showering facilities with hot water and soap are mandatory.

Safety on the job is everyone's business. Accidents are caused; they don't just happen. Constant alertness and observance of safety practices will help prevent disasters. Emergency telephone numbers should be available to all employees. The ABCs of safety are Always Be Careful!