Pollution prevention opportunities abound for POTWs. However, the P2 opportunity that is the focus of this topic hub is:

• Pretreatment programs designed to reduce the toxicity of the waste stream focusing on industrial wastes and fecal wastes

What Is A Pretreatment Program?
Federal law mandates pretreatment Programs. The Regional Water Quality Board mandates the Program as part of the SCRWA Plant's permit to operate and discharge. The Program's intent is to control pollutants discharged to a Publicly Owned Treatment Works (POTW) from non-domestic sources. The Clean Water Act of 1972 sets forth the following objectives:

• To prevent upset, interference(1) and pass-through(2) in the POTW. Specifically,
  the SCWRA Plant.
• Provide protection with regard to the health and safety of the public and the environment.
• Provide protection of the structure and integrity of the collection system and safety for the
  personnel working the system.
• To prevent deterioration of the quality standards of the receiving waters; to prevent contamination
  of POTW sludge which could affect their disposal or future use.

1 Interference - A discharge by an Industrial User which inhibits or disrupts the treatment plant processes or operations.
2 Pass-Through - The discharge of pollutants through the treatment plant which causes a violation of any requirement of the treatment plant's permit from the State regulatory agency (the Regional Water Quality Control Board).

What is Source Control?
Source control is a term used to describe activities which reduce or eliminate wastewater and pollutants that would otherwise exit the manufacturing process and enter the wastewater treatment facility. One approach to source control, pollution prevention, focuses on preventing the generation of wastes, while waste minimization refers to reducing the volume or toxicity of hazardous wastes.

While individuals and homeowners contribute to pollution that enters municipal POTWs, industrial users are the largest contributors. For information on source control for homeowners and individuals, click here: P2 Tips for Household Hazardous Waste.

Pretreatment limits may be met by industry through pollution prevention/waste minimization (e.g. material substitution, recycling and reuse of materials, treatment or process modification). These efforts may also be termed source control.

The benefits of source control in addition to protection of the public and the environment are cost savings to the industry as a result of reduced chemical and water use, reduction in disposal costs and liability, and potential reduction in the size of a pretreatment system.

What are the objectives of the Pretreatment Program?
There are three primary reasons:

• To prevent the introduction of pollutants into POTWs that will interfere with the
  operation o f the POTW, including interference with its use or disposal of biosolids;
• To prevent the introduction of pollutants into POTWs that will pass through or are
  incompatible with the treatment works;
• To improve opportunities to recycle and reclaim municipal and industrial wastewater
  and biosolids.

What Does Pretreatment Mean?
Pretreatment is the reduction of the amount of pollutants, the elimination of pollutants, or the alteration of the nature of pollutants in wastewater to a less harmful state prior to discharge to the treatment plant.

How Is the Pretreatment Program Implemented?
The Pretreatment Program is implemented through the Industrial Waste Discharge permit issued to businesses. The program is implemented through three elements in the permit: prohibited discharge standards, national categorical standards, and local limits. Permit conditions are authorized by Chapter 19 of the Gilroy City Ordinance and Chapter 13 of the Morgan Hill City Ordinance.

Who Is Required To Have An Industrial Waste Discharge Permit?
All existing commercial, institutional, and industrial users of the public sanitary sewer system. Examples: restaurants, hospitals, car wash, dental offices, medical offices, dry cleaners, printing shops, electronic components firms, etc.

What Is An Industrial User?
An industrial user is any non-residential discharger. An industrial user may not have any industrial wastewater, and may only have regular (domestic) sewage. However the pretreatment program applies to all non-residential dischargers because they have the potential to discharge other wastes to the system.

What Is An Industrial Waste?
Any non-domestic liquid or solid waste from any producing, manufacturing, processing or operation of a commercial, industrial, or institutional establishment of whatever nature. Industrial waste is distinct from sanitary or domestic waste.

When Are Industrial Users Required To Obtain A Permit?
All industrial users proposing to connect to or to contribute to the municipal sanitary sewer system shall obtain an industrial waste discharge permit before connecting to or contributing to the municipal sewer system. The Program, however, only issues a permit certificate to actual dischargers that actually have an industrial waste. Many users of the system, like a retail shop or an office, may not have to obtain a permit certificate. This assessment is made during the Business License application and building permit application processes. See the list below for examples of businesses that have to obtain a permit certificate.

• Vehicle Related Businesses (Automotive, Aircraft, Boat, Truck or Tractor): Car
  Washing, Steam Cleaning, Parts Washing, Radiator Repair, Detailing, Painting,
• Any Commercial Cooking: Bakeries, Caterers, Deli's, Restaurants, Fast Food Establishments,
  Halls And Auditoriums With Kitchens
• Cleaners, Dry Cleaners, Laundries, Laundromats
• Food Processing, including Breweries, Dairies, Wineries
• Furniture: Repair, Painting, Stripping
• Hospitals: Convalescent, Medical, Emergency, Veterinary
• Animal Care: Kennels, Grooming
• Laboratories: Chemical, Medical, Research and Development
• Manufacturing:
• Medical: Chiropractors, Dentists, Physicians, Veterinarians
• Paper, Wood or Metal Processing, Cutting, Machining, Coating, Painting, Polishing
• Photography: Film Processing, X-Ray Developing, Dark Rooms
• Art Studious: Ceramics, Painting, Pottery
• Printing/Copy Shops

Industrial Wastewater Treatment Methods
There are three general treatment methods for industrial wastewaters: Physical, chemical and biological treatment. Physical treatment methods consist of processes such as membrane technologies, carbon adsorption, distillation, filtration, ion exchange, oil and grease skimming, oil/water separation, sedimentation, steam stripping, and solvent extraction. Membrane technologies, such as ultrafiltration and microfiltration are currently popular physical treatment technologies. Chemical treatment methods include: Chemical oxidation, chemical precipitation, chromium reduction, coagulation, cyanide destruction, dissolved air flotation electrochemical oxidation, flocculation, hydrolysis, and neutralization (pH control). Biological treatment methods include: biological nitrogen removal, bioaugmentation, activated sludge, extended aeration, anaerobic processes, rotating biological contactors, sequencing batch reactors and trickling filters.

Water Reuse, Pollution Prevention and Waste Minimization
For many industries water reuse, pollution prevention and waste minimization are being increasingly utilized. Pollution prevention, focuses on preventing the generation of wastes, while waste minimization refers to reducing the volume or toxicity of hazardous wastes. Water reuse involves reusing or treating and reusing wastewater in manufacturing or other processes at a facility. Many companies are also substituting materials used in production processes with more environmentally friendly materials. Industries are now realizing that a leaner, greener, and safer company can also contribute to cost savings, positive recognition and customer satisfaction. Regulatory agencies are finding ways to reduce regulatory burdens for "green industries".

Industrial User Evaluation/Pretreatment Programs
Working closely with your industries creates an awareness on both sides of potential problems and the cause and effect of industrial discharges on the treatment plant. A good relationship with your industries also fosters communication which can help reduce the impact of problems that do occur. It also gives you the opportunity to promote pollution prevention within your community.

• Regularly update your industrial user survey to determine what industries
  are tributary to the POTW (and/or CSOs).
• Identify the pollutants of most concern and the industries most likely to be
  a source of those pollutants.
• Target one or more industrial groups per year for pollution.
• Schedule a workshop/training/brainstorming session with one or more industries.
• Incorporate voluntary P2 conditions into permits and renewals, as well as into compliance
  agreements and corrective action plans.
• Train industrial inspectors in basic pollution prevention, particularly in the types of industries
  that operate in your municipality. This can also include other inspectors, including fire department
  personnel and city code inspectors.
• Incorporate pollution prevention advice into routine pretreatment inspections (e.g. less hazardous parts
  cleaning methods, equipment cleaning and maintenance practices, reuse of materials, etc.)
• Encourage hazardous waste generators to participate in pollution prevention training programs.
• Promote material exchange between industries for usable waste materials (pallets, packaging materials,
  still usable chemicals and byproducts of production are examples).

For industry specific tips on Pollution Prevention, click here

P2 OPPORTUNITIES BY CHEMICAL
A critical element of any successful pre-treatment program is chemical-specific information that is available to both POTW employees and the industry in general. The provided list details information on both the environmental hazards and the P2 opportunities associated with certain chemicals. A list of references and help sites is also included. Click here for more information

Sources:
City of Gilroy, Ca. http://www.ci.gilroy.ca.us/

EPA - Effluent Guidelines - Zero Discharge http://www.epa.gov/ost/guide/p2/faqs2.htm

EPA - Mercury Pollution Prevention at POTWs and other Resources
http://www.epa.gov/toxteam/potwp2.htm

Illinois Environmental Protection Agency – Pollution Prevention for POTWs
http://www.epa.state.il.us/p2/fact-sheet/p2-for-potw.html

Pretreatment Program Home Page
http://www.deq.state.or.us/wq/pretreatment/pretreatment.htm

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