Wastewater Treatment Plants

Wastewater may also contain high levels of the nutrients nitrogen and phosphorus. Different treatment processes are required to remove nitrogen and phosphorus. A release of effluent containing high concentrations of these nutrients can harm the environment and human health. They can cause the overgrowth of algae or lead to the growth of toxic blue-green algae, harming aquatic life. Some algal species produce toxins that contaminate drinking water supplies.

Concrete tanks used to process wastewater can develop cracks. If cracks are not immediately repaired, contents can emanate from the process tank and contaminate underlying soil and groundwater, resulting in on-site contamination, leading to third-party property damage from contaminants migrating off-site and contaminating groundwater that may be a drinking water source.

Underground and aboveground storage tanks store process materials and wastes on-site. Underground storage tanks may leak over time, and the contents have the potential to contaminate the underlying soil and groundwater. Aboveground tanks have the potential to present problems such as leaks from tank bottoms, ruptures causing a catastrophic release of tank contents, and spills during the loading or unloading process.

Sludge generated as a by-product of the treatment process can pose potential environmental and public health risks. Sludge may contain high levels of pathogens, nutrient pollutants, chemicals, and heavy metals, depending on the composition of the wastewater from which it was produced and the treatment process used. A release or leaching from on-site storage or during sludge processing, such as dewatering, digestion, composting, and incineration, can result in soil, water, and air pollution.

Processed sludge suitable for disposal or land application can retain contaminants like phosphorus, heavy metals, and chemicals. A release of sludge during transporter loading and unloading can result in environmental cleanup, third-party liability, and natural resource damage. Treatment facilities can also be responsible for the proper use or disposal of the sludge they produce. Wastes brought to landfills can expose facilities to disposal liability. Sludge used in the land application could create a product’s exposure. If the facility performs the land application, they can carry an off-site service exposure, including improper application or over-application of nutrient pollutants.

Hazardous chemicals may be used, stored, and disposed of as part of the treatment and disinfection process. Materials include chlorine, ammonia, sulfuric acid, hydrochloric acid, and sodium hypochlorite. Containment breaches, spills, or improper handling and disposal can lead to environmental liability. Chlorine gas is highly poisonous and could kill people near a release. Chemicals should be properly segregated during storage, as incompatible materials can create hazards.

Odors produced can be a nuisance and irritant to neighboring properties, resulting in claims for third-party bodily injury or diminution of property value. The use of chemicals such as ammonia and chlorine and gases produced during treatment, such as hydrogen sulfide, can cause eye, nose, and throat irritation, headache, nausea, cough, chest tightness, nasal congestion, and stress, and could aggravate existing medical conditions such as asthma.