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Preventing Waste Water Pollution

Where does the water go after you flush the toilet or drain the sinks in your home? 

When the wastewater flushed from your toilet or drained from your household sinks, washing machine, or dishwasher leaves your home, it flows through the City's sanitary sewer system to the  Monterey One Water (fornmerly MRWPCA) Regional Treatment Plant in Marina. The wastewater from homes, along with wastewater from businesses, industries, and other facilities, is treated by a variety of processes to reduce or remove pollutants. 

What happens to the treated water when it leaves the wastewater treatment plant? 

The Regional Treatment Plant treats and recycles approximately 60% waste water collected in the MRWPCA service area for reuse by the agricultural industry in northern Monterey County. The remaining 40% of treated waste water is discharged into the Monterey Bay. 

Learn how to properly dispose of the following items to prevent water pollution:

Disposable Wipes 
Disposable cleaning and disinfecting wipes do not break down quickly in water. If flushed, they can clog your sewer line of the public sewer systems, potentially causing sewage overflows which can put public health at risk, damage the environment, and cause property damage. 

If you use disposable cleaning/disinfecting wipes, moist towelettes, baby wipes, personal hygiene wipes or similar disposable or "flushable" products, put them in the trash, never in your toilet.

Wipes are NOT biodegradable, and have to be manually removed from the equipment at wastewater treatment plants and sent to the landfill. 

See the effect of disposal wipes on a California water treatment plant in this video.

Fats, Oils, and Grease (FOG) 
Grease is one of the leading causes of clogs and sewage overflows. Cooking fats, oils and grease cool and congeal inside sewer pipes and build up over time. Eventually, the pipe becomes clogged so that wastewater can’t flow through it. 

For more information on how to properly dispose of fats, oils and grease see: Clogbusters 

Household Cleaners 
Most households contain a wide variety of cleaning products, disposable wipes, and first aid kits. These may contain harsh chemicals, which when washed down the drain, can mix with other chemicals present in the sanitary sewer. There they form toxic gases and compounds that can flow to the wastewater treatment plant and negatively impact the treatment processes. Chemicals from cleaning products can also pass through the plant and negatively affect organisms and vegetation in the Monterey Bay. 

Many toxic and harmful commercial cleaners, bug killers and weed killers can be replaced by less harmful products. See the Monterey One Water website for alternative household solutions.

Household Hazardous Waste 
All hazardous products exhibit at least one of the following properties: 



Toxic: even in small quantities may immediately poison, or cause injury or death through repeated exposure, when inhaled into the lungs, eaten, swallowed, or absorbed through the skin (e.g. rat poison, pesticides, bleach). 
  Flammable Flammable: usually liquids that easily ignite and burn (e.g. lighter fluid, spot and paint removers). 
  Corrosive Corrosive: substances or vapors that can burn skin on contact and can eat away the surface of other materials (e.g. oven and toilet bowl cleaners). 
  Reactive: substances that react with air, water or another substance to produce toxic vapors or explode (e.g. bleach when mixed with ammonia-based cleaners). 

Household hazardous wastes should never be flushed into down sewer drains because these wastes can kill the active bacteria at the waste water treatment facility. Wastewater treatment plants are not designed or able to handle many of these hazardous wastes. Wastewater treatment facilities cannot remove all heavy metals and these may contaminate sewage sludge, water supplies and animal habitats. 

The Monterey Regional Waste Management District offers residents a convenient and safe collection program for household hazardous waste 

Mercury from thermometers, thermostats, certain kinds of switches and blood pressure cuffs can pollute the Monterey Bay. These items should not be disposed of in the trash either, because mercury from broken devices can vaporize into the air. Instead bring mercury devices to a collection site. 

The Monterey Regional Waste Management District offers residents a convenient and safe collection program for household hazardous waste 

Flushing prescription medicines down the toilet may not be removed during the wastewater treatment process and could heavily affect our wildlife after it is discharged into the bay and ocean. 

The Monterey County Health Department has guidelines and information about safe and proper disposal and drop off locations.