§ 12A-3-2 Additional pretreatment measures.
(A) The Director may require Users to restrict their discharge, designate that certain wastewater be discharged only into specific sewers, relocate and/or consolidate points of discharge, separate sewage waste streams from industrial waste streams, and such other conditions as may be determined necessary by the Director to protect the POTW and determine the User’s compliance with the requirements of this chapter.
(B) The Director may require any person discharging into the POTW to install and maintain, on their property and at their sole expense, a suitable storage and flow control facility to ensure equalization of flow. A wastewater discharge permit may be issued solely for flow equalization.
(C) The Director may require Users, which includes food preparation facilities, to install grease, lint, sand/oil interceptors, oil/water separators, hair or grease trap(s) as needed for the proper handling of wastewater containing excessive amounts of fats, oils, grease, lint or sand; except that such interceptors or traps shall not be required for residential users. Requirements for the proper handling of fats, oils, grease, lint, sand and solids in wastewater are as follows:
(1) Grease interceptors and grease traps shall be required, installed, and maintained as specified in this article for the sizing and cleaning of interceptors and traps for the food preparation establishments.
(2) Lint, sand/oil interceptors and oil/water separators shall be installed in compliance with the City code.
(3) All interceptors, separators and traps shall be of the type and capacity approved by the Director and shall be located to be easily accessible for cleaning and inspection. Interceptors, separators and traps shall be inspected, cleaned, and repaired regularly by the user at the user’s expense. The User shall keep records of all cleaning, repair and maintenance for at least three years. Such records shall be readily available for inspection by the Director upon request at no expense to the City.
(4) The User shall be responsible for reimbursing the City for any and all expenses, costs, and penalty fees and fines for the cleanup of any sanitary sewer overflow from the Sewer System as a result, directly or indirectly, of the User actions.
(D) The method for determining the size of traps or interceptors is the drainage fixture unit value. The minimum size for all interceptors is a capacity of 500 gallons and the maximum size for all interceptors is a capacity of 2,500 gallons. Interceptors must be constructed with at least two chambers. Sizing for all traps is a minimum of a 50 gallon per minute, 100 pound capacity with the flow control valve installed in a manner that provides access at all times. The appropriate size for interceptors and traps is determined as follows:
(1) Interceptor Sizing. The interceptor shall be sized using the drainage fixture-unit value as defined in the following table. Using the drain outlet or trap size, these sizes are converted to discharge rates on the basis that one fixture-unit equals 7.5 gpm.
|
Fixture Outlet or Trap Size (Inches) |
Drainage Fixture-Unit Value |
GPM Equivalent |
|---|---|---|
|
1 1/4 |
1 |
7.5 |
|
1 1/2 |
2 |
15.0 |
|
2 |
3 |
22.0 |
|
2 1/2 |
4 |
30.0 |
|
3 |
5 |
37.5 |
|
4 |
6 |
45.0 |
|
Floor Drains (All Sizes) |
2 |
15.0 |
|
Dishwashers |
Double Size |
(2) Calculating Interceptor Size. Formula to calculate the size of the interceptor is:
(a) Determine total fixture-unit value by multiplying fixture type count by drainage value;
(b) Total all values;
(c) Determine total flow by multiplying total value by flow rate of three gpm;
(d) Multiply total flow by 12; and
(e) Round up to the next nearest size interceptor.
(3) Requirements for Interceptors. The interceptor shall be:
(a) A minimum of 500-gallon capacity, two chamber concrete container (fiberglass and/or other type material must be approved by the Director);
(b) When calculated to have a capacity of 750 gallons or more, the interceptor must have three chambers, each with a manway;
(c) Constructed with inlet piping with a 90-degree elbow and minimum of an 18-inch down spout;
(d) Constructed with outlet piping with a tee connection and a threaded cover with a minimum of an 18-inch down spout;
(e) Installed with a two-way clean-out within five feet before and five feet after the interceptor; and
(f) Constructed with the appropriate traffic-rated cover. The cover(s) must not be marked with any wording indicating it is owned by the City of Goodyear.
(g) Grease and oil interceptors shall be constructed of impervious material capable of withstanding abrupt and extreme changes in temperature. They shall be of substantial construction, watertight and equipped with easily removable covers which, when bolted in place, shall be gas-tight and watertight.
(h) Lockable shut-off valves shall be provided between interceptors and service taps into sewer mains where required by rules and regulations promulgated by the Director.
(4) Grease Trap Installation and Sizing. Grease traps are allowed only when there are four or fewer than four fixtures used for food preparation. Any facility installing a dishwasher shall install a grease interceptor. For the purpose of sizing a grease trap, a fixture means the entire unit, e.g., a three-compartment sink is considered one unit. Grease traps must be installed as follows:
(a) A grease trap shall be installed whenever a three-compartment sink is required by Maricopa County;
(b) The minimum size grease trap to be installed shall be rated no smaller than 50 gallon-per-minute with a 100-pound grease capacity; and
(c) A flow restriction valve shall be installed upstream of the grease trap and vented properly. If placed below floor level the flow restriction valve must be installed in a manner which allows for inspection and maintenance.
(E) All grease traps, oil, sand, and grease interceptors shall be pumped out or cleaned out completely at least once every 180 days, or more frequently as required by the City, unless otherwise authorized in writing by the Director.
(F) Except for residential sources, users shall not install or replace equipment designed to convert garbage or solid waste into liquefied waste and introduce such waste into the POTW by means of a garbage grinder/disposal. Garbage and solid waste shall be disposed of as provided in Chapter 10 of the Goodyear City Code.
(G) Administrative and penalty fees and costs will be assessed by the City for the inspections and tracking compliance with this subsection. (Ord. 14-1290, passed 3-3-2014; Am. Ord. 23-1584, passed 9-25-2023)