Stay Informed

Show All Answers

1. What are prohibited discharge standards?

A person may not discharge pollutants to the POTW that cause:
- A flow rate or quantity that exceeds the carrying capacity of the collection system
- A hazard to property, public health, or safety
- A treatment plant upset
A violation of a permit issued under this chapter
- Damage to the POTW
Interference with the operation of the POTW
- Pass through or contribute to pollution of the POTW’s receiving waters
- The ambient air quality of the POTW to exceed standards established by federal, state or local law
- The concentration of pollutants in the POTW or in the POTW's sludge to exceed allowable limits
- The POTW to be in violation of the NPDES permit or TPDES permit

2. What are categorical pretreatment standards?

Categorical Pretreatment Standards limit the pollutant discharges to POTWs from specific process wastewaters of particular industrial categories. These national technology-based standards apply regardless of whether or not the POTW has an approved pretreatment program or the IU has been issued a control mechanism or permit. Such industries are called Categorical Industrial Users.

The standards are promulgated by EPA in accordance with Section 307 of the Clean Water Act and are designated in the Effluent Guidelines & Limitations [Parts 405-471] by the terms "Pretreatment Standards for Existing Sources (PSES)" and "Pretreatment Standards for New Sources (PSNS)."

3. What are local limits?

Local limits are wastewater limitations that apply to commercial and industrial facilities that discharge to a publicly owned treatment works (POTW). Local limits are developed to meet the pretreatment program objectives and site-specific needs of the local POTW and the receiving stream.

Local limits control the pollutants in the wastewater discharges from commercial and industrial facilities and apply at the "end-of-pipe" from the facility. The regulations under 40 CFR §403.5 (d) give the POTW the authority to enforce its local limits.

4. Who needs to develop local limits?

The following POTWs are required by 40 CFR §403.5 (c) to develop local limits:
- POTWs required to implement an approved pretreatment program need to develop local limits, or demonstrate that they are not necessary
- Other POTWs where wastewater discharges from commercial and industrial facilities have caused interference or pass through, and such violation is likely to recur
- This requirement is contained in the POTW’s National Pollution Discharge Elimination System (NPDES) permit

5. What is wastewater?

Wastewater is used water. It includes substances such as human waste, food scraps, oils, soaps and chemicals. In homes, this includes water from sinks, showers, bathtubs, toilets, washing machines and dishwashers. Businesses and industries also contribute their share of used water that must be cleaned.

6. How is wastewater treated?

The wastewater is treated by means of mechanical separation, gravity, and biological treatment. As the wastewater enters our treatment plant, it flows through the head works. Inside the head works is a screen that captures large pieces conveyed by the stream (trash, clothing, etc.). The flow then passes through the grit classifier. This is an aerated area that allows small pieces of waste that are heavier than water to fall out.

Flow then enters our primary clarifier. The primary clarifier removes solid material and float able portions of the wastewater. Wastewater proceeds to the aeration basins where nitrogen and phosphorus removal occurs. The final step is disinfection by chlorination. Solids from this process are treated in digesting structures, then hauled to a local farm for use as crop nutrients.

7. What if my sewer is not flowing normally?

When you flush your toilet, run your washing machine, or use your sink, you expect it to drain. What should you do if it is not draining? The first step is to determine if the issue is affecting your entire house. If only one drain or one room is affected, then it may be an issue inside of your house. If this is the case attempt to fix the issue yourself or contact a plumber.

If every drain is affected, it may be an issue in your lateral line or the City’s main line. It is your responsibility from your house to where your service lateral is connected to the sewer main including your service tap to the main line. If our line is clear, you will need to investigate on your own or contact a plumber to determine the issue. To check your line, you may contact the city at any time.

8. How often should I clean my grease trap or grease interceptor?

Every restaurant, cafeteria, or large non-residential kitchen is required to have a functioning grease removal system (GRS) in place. Grease removal systems help protect users and the city’s pipes by removing grease, oils, and solids prior to discharge. For these to function efficiently, they must be serviced regularly.

These devices come in 2 general types. The first and smaller type is a grease trap, which are commonly made of plastic or metal and are located near 3 compartment sinks. These are required to be emptied, checked, and at least cleaned once per week. Some might be need cleaning daily

The 2nd type of GRS is a grease interceptor. These are larger in ground units with capacities that range from 1,000 to 1,500 gallons. Depending on the type of restaurant and number of customers they might need pumped once a week , month or even greater. Our pretreatment monitor is willing to meet with you to discuss this and help you do an inspection on your interceptor .

Each time a GRS is serviced it must be documented. This form is to be signed and sent to the Sewer Department quarterly (January, April, July and October). Should you have any comments or questions please contact the Wastewater Department.