Influent[edit | edit source]

Water10.jpg Raw Influent

Sources[edit | edit source]

The most common sources of Raw influent (sewage)is waste liquid from toilets, baths, showers, kitchens, sinks,etc., that is disposed of via sewers. Raw influent can also come from industrial sources in coverage area of treatment plant.

Composition[edit | edit source]

Influent is composed of anything that you could possible put down your household drains and any liquid output, not deemed[Hazardous waste[1]], from factories in the area. This may include:

  • water(majority of influent)
  • cleaning products
  • human waste
  • paper
  • hair
  • food
  • anything that goes down the drain in a household
  • anything in rain runoff that infiltrates the storm drains

Influent is 99.94 percent water, with only 0.06 percent of the influent dissolved and suspended solid material. The cloudiness of influent is caused by suspended particles which, in untreated influent ranges from 100 to 350 mg/l. A measure of the strength of the influent is biochemical oxygen demand, or BOD5. The BOD5 measures the amount of oxygen microorganisms require in five days to break down sewage. Untreated sewage has a BOD5 ranging from 100 mg/l to 300 mg/l. Pathogens or disease-causing organisms are present in sewage. Coliform bacteria are used as an indicator of disease-causing organisms. Sewage also contains nutrients (such as ammonia and phosphorus), minerals, and metals. Ammonia can range from 12 to 50 mg/l and phosphorus can range from 6 to 20 mg/l in untreated sewage.-Karen Mancl,"Wastewater Treatment Principles and Regulations"[[2]]

Impact of heavy storms[edit | edit source]

During heavy rain or snow melt months, additional water produced by the conditions can infiltrate the sewer systems and overload the wastewater treatment plant. The Arcata marsh can hold 5 times the amount normally treated during these rainy months.This is a serious concern in areas that are prone to these conditions. The Arcata marsh has a system set up to anticipate heavy rains that could overload the system with too much water. The Engineers at the plant have to make room in the tanks during anticipated rainy months, to hold the added amount of water that will flow into the plant via sewage drains.

Rules and Regulations[edit | edit source]

the EPA is in charge of making rules and regulations for the disposal of municipal wastewater through a bill called the clean water act. [3] This act makes cities accountable for the proper disposal of waste. It's main objective is to keep our fresh water and oceans unpolluted.

Destination[edit | edit source]

We have to control what becomes of our wastewater.

Badbeach.jpg Unusable environment

We control wastewater by setting up a sewage system. The influent runs through sewage lines underneath the city put into place by cal trans[[4]] to the Arcata wastewater treatment plant, and their primary treatmentArcata_marsh_primary_wastewater_treatment.