(a) 
Grease traps, interceptors, separators, or holding tanks shall be provided for the proper handling of wastes containing grease, oil, sand, and other harmful pollutants which may interfere with the operation and maintenance of the POTW and shall be constructed and maintained in accordance with the provisions outlined in the city Code of Ordinances.
(b) 
All restaurants, institutions, cafeterias, or other establishments preparing or serving food to the general public shall be required to install and maintain a grease trap for the efficient removal of oil and grease from the waste stream. The design and installation of such devices shall be subject to review and approval by the city manager.
(c) 
All vehicle wash areas shall be equipped with interceptors and oil separators for the removal of oils, grease, and sand and other solids. The design and installation of such devices shall be subject to review and approval by the city manager.
(d) 
It shall be the responsibility of the user to furnish, operate and maintain such pretreatment devices as necessary to produce an effluent in compliance with this article or other applicable ordinances.
(e) 
Holding tanks shall be provided for waste oils and other objectionable waste that is prohibited from being discharged into the POTW, such as phosphates and vegetable debris. Such holding tanks shall be constructed to prevent leakage and splashing and shall be equipped with secondary containment to prevent spills during operation and cleaning. Such tanks shall be maintained to preclude odor and other nuisances and shall not be connected to the POTW or in any other way allowed to be discharged to the POTW.
(Ordinance 395, sec. 2, adopted 7/21/15)
(a) 
Existing facilities required by this article or other applicable ordinances to maintain a grease trap, interceptor or separator not equipped with an adequately sized treatment unit shall, within eighteen (18) months of the effective date of this article, install an adequately sized grease trap, interceptor or separator in accordance with the specifications of this article.
(b) 
Existing facilities required by this article or other applicable ordinances to maintain a grease trap, interceptor or separator not equipped with the required pretreatment device for the type of business shall, within nine (9) months of the effective date of this article, install an adequately sized grease trap, interceptor or separator in accordance with the specifications of this article.
(c) 
In any circumstance where, in the opinion of the city manager, the existing grease trap, separator, or interceptor or the absence of a grease trap, separator, or interceptor poses a serious threat or an ongoing problem to the sanitary sewer, is a public nuisance, or poses a threat to public health or to the environment, the city manager shall require the grease trap, interceptor, or separator to be installed or replaced as and when necessary to remediate the threat.
(d) 
If a food establishment or any other facility requiring a grease trap, interceptor, or separator shall cease operation and shall be required to come into compliance with other city codes, then such establishment or facility shall be required to comply with this article before reopening.
(Ordinance 395, sec. 2, adopted 7/21/15)
New businesses required by this article or other ordinance to maintain a grease trap, interceptor or separator shall install such unit prior to commencement of discharge to the POTW.
(Ordinance 395, sec. 2, adopted 7/21/15)
(a) 
All nondomestic users shall request a determination from the city manager whether a new or upgraded grease trap, interceptor or separator will be required for his facility. The city manager may approve alternate treatment technologies for some types of wastes normally treated by a separator.
(b) 
Where a user requests his facility not be required to install a grease trap, interceptor or separator, the city manager shall require data demonstrating the user is able to comply with the limitations outlined in this article or other applicable ordinances. The user may be subject to periodic monitoring to demonstrate continued compliance. Requests not to install a grease trap, interceptor or separator must be approved by the city manager.
(c) 
Where a user requests the use of alternate technology, the city manager shall require data demonstrating the user is able to comply with the standards contained herein and in other applicable ordinances. The user may be subject to periodic monitoring to demonstrate continued compliance.
(d) 
Such approvals shall be made on a case-by-case basis.
(e) 
The decision of the city manager can be appealed to the city manager. The decision of the city manager is final [sic].
(Ordinance 395, sec. 2, adopted 7/21/15)
(a) 
Specifications outlined in this article shall be considered minimum requirements only. It shall be the responsibility of each user to have a grease trap, interceptor, or separator designed and installed and maintained that will produce an effluent in compliance with the requirements of this article or other applicable ordinances.
(1) 
Grease traps, interceptors, and separators shall meet or exceed the more stringent of specifications and requirements set forth in this article and other applicable local, state, or federal requirements.
(2) 
An existing grease trap, interceptor, or separator which is upgraded or replaced shall meet or exceed the specifications set forth in this article and other applicable local, state, or federal requirements.
(3) 
Where a nondomestic user required under this article to have a grease trap, interceptor, or separator will occupy an existing building, the grease trap, interceptor, or separator shall meet or exceed the requirements in this article and other applicable local, state, or federal requirements.
(b) 
Grease traps, interceptors, and separators shall be constructed of impervious materials capable of withstanding abrupt and extreme changes in temperature and capable of withstanding the traffic load where installed.
(c) 
Grease traps, interceptors, and separators shall be installed outside the building wherever possible. Where it is impossible to locate a grease trap outside the building, the trap shall be located in a mechanical room or other separate area where no food is stored or processed.
(d) 
Grease traps, interceptors, and separators shall be located so as to be readily and easily accessible for cleaning and inspection of the pretreatment device and shall be equipped with easily removable covers.
(1) 
Manhole rings and covers, not less than twenty-four (24) inches in diameter, shall be installed in the lid of each compartment to facilitate easy access for cleaning and inspection. The manholes shall be placed so that all internal piping is accessible for maintenance and inspection. The cover shall be at or near, but not below, the finished grade.
(2) 
Where an existing interceptor or separator is located inside a vehicle wash bay, the first chamber shall be preceded by a grated catchbasin with openings not greater than one-half (1/2) inch in diameter or shall be equipped with a grated cover with openings not greater than one-half (1/2) inch in diameter so that no solid material greater than one-half (1/2) inch in diameter may enter the chamber. The cover on the secondary chamber shall be watertight. Where the interceptor or separator is preceded by a grated catchbasin, all covers on the separator shall be watertight.
(e) 
Grease traps shall have a total liquid capacity of not less than five hundred gallons unless the user has demonstrated and received approval from the city manager for a smaller capacity. Interceptors shall have a total liquid capacity of not less than fifty (50) gallons. Separators shall have a total liquid capacity of not less than five hundred (500) gallons. Grease traps and separators shall be constructed with a minimum of two (2) compartments.
(1) 
The primary compartment shall have a detention time at peak flow of not less than fifteen (15) minutes.
(2) 
The secondary compartment shall have a detention time at peak flow of not less than five (5) minutes.
(f) 
Plans for new grease traps, interceptors, and separators or modifications to existing grease traps, interceptors, and separators shall be submitted to the city manager and the city plumbing inspector for review.
(1) 
A description of plumbing fixtures draining to the trap, the number of fixture units as determined by the plumbing inspector and the calculations used to determine the proposed capacity shall be included in the submittal.
(2) 
The city manager and the plumbing inspector shall be in agreement for approval of the final plans prior to the issuance of any required plumbing or construction permits and subsequent construction.
(g) 
All grease traps, interceptors and separators shall be equipped with an approved sampling port immediately downstream of the treatment facility. Existing facilities without an approved sampling port shall be equipped with an approved sampling port within twenty-four (24) months of the effective date of this article.
(1) 
Sampling ports shall be easily accessible and safely located and shall be constructed in accordance with plans approved by the city manager. Sampling ports shall be inspected by the city manager prior to use.
(2) 
Sampling ports shall be installed by the owner at his expense and shall be maintained by him so as to be safe and accessible at all times.
(3) 
Sampling ports shall be constructed to exclude the entry of stormwater and groundwater and the exit of wastewater (prevention of infiltration/inflow, exfiltration/exflow).
(h) 
Grease traps, interceptors, separators and sampling ports shall be installed by a licensed plumber. Completed grease traps, interceptors, and separators shall be subject to inspection by the city manager and the plumbing inspector prior to connection to the POTW.
(Ordinance 395, sec. 2, adopted 7/21/15)
(a) 
All liquid waste lines in food preparation and dishwashing areas, except lines from restroom facilities, cooling unit condensate, icemakers, and soft drink dispenser drain lines, shall discharge through the grease trap.
(b) 
The minimum size of grease traps shall be determined according to the number of fixture units draining through the trap, but shall, in no case, have a total liquid capacity of less than five hundred (500) gallons unless the user has demonstrated and received approval from the city manager for a smaller capacity. If the city manager has not approved a small capacity then the capacity will be determined by:
(1) 
The total number of fixture units multiplied by one hundred and fifty (150) gallons shall determine the minimum total liquid capacity of the trap.
(2) 
The primary chamber shall occupy three-fourths (3/4) of the total liquid capacity of the trap.
(3) 
The dividing wall between each chamber shall completely divide the chambers (shall extend top to bottom) except where the specific design of the separator provides for underflow, in which case the wall shall not be greater than twelve (12) inches from the bottom between the chambers rather than the flow traveling through a pipe.
(4) 
Fixture unit types and fixture unit counts are located on the city grease trap sizing criteria table (section 13.05.050).
(c) 
Grease traps shall be equipped with double cleanouts on the outside of the trap in both the influent (prior to the trap) and effluent (after the trap) pipes.
(d) 
The influent shall enter each chamber below the static water level in accordance with the specifications outlined in this section. The effluent shall discharge from below the static water level of the chamber in accordance with the specifications outlined in this section.
(1) 
The influent line into all chambers shall terminate no greater than eighteen (18) inches from the bottom of the chamber.
(2) 
The effluent from all chambers shall discharge from the lower twelve (12) inches of the chamber.
(3) 
There shall be no openings in any influent or effluent pipe that will allow liquid to enter or exit the chamber at any point other than the intake or discharge point of the pipe.
(4) 
The static water level shall be maintained throughout the entire trap.
(Ordinance 395, sec. 2, adopted 7/21/15)
(a) 
Automatic car or truck washes and coin-operated wash bays, drive-in or drive-through wash bays, hand wash bays and other areas where vehicles are washed shall be equipped with an interceptor and a two-stage separator. The interceptor and the separator shall function as separate units.
(1) 
An adequately sized interceptor shall be provided for the removal of sand, grit and other objectionable solids from the waste stream.
(2) 
An adequately sized two-stage separator shall be provided for the removal of oil and grease from the waste stream.
(3) 
Interceptors and separators shall be minimally sized in accordance with the specifications outlined in this article. Minimum sizing for any interceptor or separator may be increased at the discretion of the city manager when necessary to protect health, safety and property or to carry out the purposes and intents of this article.
(b) 
Interceptors shall have a minimum detention time of not less than five (5) minutes. The minimum size shall be in accordance with the specifications outlined in this article.
(1) 
Interceptors may be located inside the wash bay and may be equipped with a grated cover provided the openings in the cover are not greater than one-half (1/2) inch in diameter or per side of a rectangle. When located inside the wash bay, the city manager may require a larger capacity interceptor be installed to facilitate efficient sand and grit removal. Covers shall be easily removable for cleaning and inspection.
(2) 
Where located outside the wash bay, the interceptor shall be equipped with solid watertight covers on each chamber and shall be preceded by a catchbasin, located inside the bay, equipped with a grated cover with openings not greater than one-half (1/2) inch in diameter or per side of a rectangle. Covers shall be easily removable for cleaning and inspection.
(3) 
The inlet and outlet lines shall be designed and installed to provide uniform flow and stilling in the interceptor and to preclude sand from passing through the interceptor.
(A) 
Where a down pipe is provided at the inlet, the pipe shall extend into the interceptor a distance not less than one-third (1/3) from the static water level to the bottom.
(B) 
The discharge pipe shall extend into the interceptor a distance not less than one-third (1/3) from the static water level to the bottom.
(c) 
Separators shall be located outside the wash bay and shall be equipped with solid watertight covers on all chambers. Covers shall be easily removable for cleaning and inspection. The influent shall enter each chamber below the static water level in accordance with the specifications outlined in this section. The effluent shall discharge from below the static water level of the chamber in accordance with the specifications outlined in this section.
(1) 
The influent line into all chambers shall terminate no greater than eighteen (18) inches from the bottom of the chamber.
(2) 
The effluent from all chambers shall discharge from the lower twelve (12) inches of the chamber.
(3) 
There shall be no openings in any influent or effluent pipe that will allow liquid to enter or exit the chamber at any point other than the intake or discharge point of the pipe.
(4) 
The static water level shall be maintained throughout the entire trap.
(d) 
Minimum sizing for interceptors shall be fifty (50) gallons per fixture unit (F.U.) draining into the interceptor, but not less than the minimum sizes outlined below:
(1) 
Manual hand wash bay or portable washer: 50 gallons/F.U. but not less than 50 gallons/bay.
(2) 
Coin-operated self-service wash bays: 50 gallons/F.U. but not less than 50 gallons/bay.
(3) 
Automatic (drive-in and drive-through): 50 gallons/F.U. but not less than 50 gallons/bay.
(e) 
(1) 
Minimum sizing for separators shall be one hundred and fifty (150) gallons per fixture unit draining into the separator, but not less than the minimum sizes outlined below:
(A) 
Portable washer: Greater of 500 gallons or 150 gallons/F.U.
(B) 
Single coin-operated wash bay: Greater of 500 gallons or 150 gallons/F.U.
(C) 
Manual hand wash, single bay only: Greater of 500 gallons or 150 gallons/F.U.
(D) 
2 to 4 coin-operated or manual hand wash bays: Greater of 1000 gallons + 200 gallons/bay or 150 gallons/F.U.
(E) 
More than 4 coin-operated or manual hand wash bays: Greater of 1000 gallons + 200 gallons/bay or 150 gallons/F.U.
(F) 
Drive-through wash bay: Greater of 500 gallons/bay or 150 gallons/F.U.
(2) 
The primary chamber of the separator shall occupy three-fourths (3/4) of the total liquid capacity of the separator.
(3) 
The dividing wall between each chamber shall completely divide the chambers (shall extend top to bottom) except where the specific design of the separator provides for underflow not greater than twelve (12) inches between the chambers rather than the flow traveling through a pipe.
(Ordinance 395, sec. 2, adopted 7/21/15)
(a) 
Holding tanks shall be constructed and maintained to prevent discharge of waste cooking oils, motor oils and other oils and fluids that are prohibited from being discharged to the POTW.
(b) 
Holding tanks shall not be connected to the sanitary sewer or in any other way be allowed to discharge to the POTW.
(c) 
Holding tanks shall be provided with secondary containment and such containment shall be capable of containing not less than one hundred and ten (110) percent of the capacity of the holding tank or the capacity of the largest tank plus water from a maximum 24-hour/10-year rainfall event if exposed to rainwater, whichever is greater.
(1) 
Secondary containment shall be constructed so as to control spills or splashes during operation and maintenance and leaks.
(2) 
Secondary containment shall not be connected to any POTW or storm drain and shall not be allowed to drain onto public or private property or to the waters of the United States.
(Ordinance 395, sec. 2, adopted 7/21/15)
(a) 
General requirements.
(1) 
Grease traps, interceptors, separators and holding tanks shall be operated in a safe and secure manner at all times.
(2) 
Areas surrounding grease traps, interceptors, separators and holding tanks shall be maintained to facilitate immediate access to the unit for cleaning and for inspection by the city manager at all times.
(3) 
Grease traps, interceptors and separators shall be maintained in continuously efficient operation by the owner or operator at his expense and shall produce an effluent in compliance with this article and other applicable ordinances.
(4) 
A user shall not remove any down pipes or otherwise alter a grease trap, interceptor or separator in any way which may allow oil, grease, sand, or other objectionable materials to pass through the device into the POTW.
(5) 
Where the city must clean associated public sewers caused by inappropriate operation or maintenance, inadequate design or installation, or inappropriate alteration of a grease trap, interceptor or separator, costs of such cleaning shall be billed to the user.
(A) 
In a case where several users are discharging to the same sewer line, all the users shall be equally liable except where the user provides written proof his discharge could not have been a contributing factor.
(B) 
Proof shall consist of demonstration of adequate sizing and installation; appropriate cleaning (as documented by manifests and inspection documentation) and valid analysis of a sample of the discharge collected within one (1) week of the sewer cleaning activities. Analysis of samples collected after sewer line cleaning will be accepted only where the grease trap, interceptor or separator has been properly maintained and was not cleaned within thirty (30) days of the sewer cleaning activities.
(6) 
A user shall not increase the use of water or in any other way attempt to dilute the waste stream in lieu of adequate treatment.
(7) 
The addition of hot water or the use of emulsifiers, chemicals, or other agents or devices that may cause oil, grease, or sand to pass through a treatment facility or into the POTW sewer collection system is strictly prohibited.
(8) 
Areas surrounding a grease trap, interceptor, separator or holding tank shall be kept clean and free of grease and odors and other materials at all times.
(A) 
Materials shall not be splashed, spilled, allowed to overflow, or otherwise placed on the area surrounding a grease trap, interceptor or separator.
(B) 
In the event materials are spilled, splashed, overflowed, or otherwise placed on the surrounding area, the generator or owner shall assure the materials are promptly cleaned from the area and properly disposed.
(9) 
Grease traps, interceptors, separators and holding tanks shall be fully evacuated of all contents during cleaning. If the capacity of the trap, interceptor, separator or holding tank is greater than the capacity of the transport vehicle where full evacuation is not possible in a single load, then the transporter and the generator shall assure the contents are fully evacuated within twenty-four (24) hours.
(A) 
No liquid waste shall be returned to the trap, interceptor, separator or holding tank after or during cleaning, either from the same or other trap, interceptor, separator or holding tank.
(B) 
During cleaning, grease residue shall be removed from piping and walls and the piping and walls shall be inspected to assure the integrity of the device is maintained.
(10) 
Materials removed from traps, interceptors, separators and holding tanks shall be utilized by industry, recycled, or disposed at a facility designated by or acceptable to the generator where the owner or operator agrees to receive the wastes and the disposal facility has documentation showing the facility meets all requirements of the state and federal authorities. All wastes shall be disposed in a suitable manner in accordance with applicable federal, state, and local laws.
(11) 
Users required to maintain grease traps, interceptors, separators, or holding tanks shall establish a system of training designed to provide employees with appropriate instruction on the proper use of such facilities.
(A) 
Such training system shall provide employees at all levels of responsibility with a complete understanding of the operation and maintenance of the pretreatment device and the relation between appropriate waste disposal and efficient operation of the pretreatment device. Such system should include:
(i) 
The importance and methods of good housekeeping practices;
(ii) 
Acceptable waste disposal practices, including proper disposal of different types of wastes;
(iii) 
Procedures for preventing prohibited discharges; and
(iv) 
The proper response to and notifications in case of spills or other accidental discharges.
(B) 
Periodic training sessions shall be conducted to assure the employee understands the essential elements of the system. New employees shall be trained immediately upon employment.
(C) 
Users required to maintain grease traps, interceptors, separators or holding tanks shall keep documentation of training available for inspection.
(b) 
Use of grease trap treatment products.
(1) 
Use of grease trap treatment products, including bacteria, designed to digest the grease, is specifically prohibited without prior written consent of the city manager.
(A) 
Acceptance of such products for use may be considered only where a valid screening test, showing the product’s ability to treat the waste and to produce an effluent in compliance with this article, has been performed in accordance with the methods outlined by the city manager.
(B) 
Screening tests for grease trap treatment products shall be designed by the city manager.
(C) 
The results of screening tests shall be subject to technical review by the city manager.
(D) 
All costs of screening tests shall be borne by the user whether or not the product is accepted for use.
(E) 
If a product is accepted for use, each user shall obtain written permission from the city manager to use the product.
(F) 
The city manager may revoke permission to use such products where the effluent from the trap or basin in which the product is used fails to meet the requirements of this article.
(2) 
Use of accepted grease trap treatment products shall not relieve the user of minimum cleaning requirements set forth in this article.
(3) 
Use of accepted grease trap treatment products may subject the user to monthly surcharge fees where such usage causes the effluent concentrations to exceed the definition of normal domestic wastewater. Surcharge fees may be levied for biochemical oxygen demand, chemical oxygen demand, total suspended solids, or ammonia.
(c) 
Inspection and cleaning schedule.
(1) 
Inspection, cleaning, and other necessary maintenance of such facilities shall be conducted as often as needed to assure the discharge is in compliance with the provisions of this article or other applicable ordinances, but not less than once per ninety (90) days.
(A) 
The trap, interceptor or separator shall be cleaned as often as necessary, up to and including daily, to assure compliance with this article or other applicable ordinances.
(B) 
In no case shall the accumulated grease, oil, or sand be allowed to occupy more than twenty-five (25) percent of the capacity of the first stage.
(2) 
The physical condition of the trap, interceptor, or separator (piping, internal walls, side walls, etc.) shall be inspected by the user each time the facility is cleaned. Repairs, if needed, shall be made prior to further use.
(A) 
Repairs or modifications shall be approved by the plumbing inspector and shall not be made without the appropriate city permits.
(B) 
Inspection shall be conducted by the plumbing inspector after repair and prior to refilling or use. A copy of the inspection tag issued by the plumbing inspector shall be maintained on site by the user and a copy shall be sent to the city manager.
(C) 
Documentation of repairs shall be submitted to the city manager within thirty (30) days of the date of repair, or earlier if specified in a notice of deficiency or other city manager-issued document.
(3) 
Grease traps, interceptors, and separators shall produce an effluent in compliance with this article at the user’s pumping schedule. Schedules inadequate to produce such effluent shall be upgraded to as often as necessary, up to and including daily, or the trap, separator, or interceptor shall be upgraded. Upgraded traps, separators, or interceptors shall meet all requirements set forth in this article or other applicable ordinances.
(4) 
A user shall have any trap, interceptor, or separator cleaned when ordered to do so by the city manager. Failure to comply within forty-eight (48) hours after the request shall be cause for the city manager to precipitate the cleaning and to bill the user for such costs plus any added costs incurred by the city.
(d) 
Cleaning schedule extensions.
(1) 
The user may apply to the city manager for an extension of the required cleaning frequency set forth in this article. A user who wishes to apply for a cleaning schedule extension shall notify the city manager, in writing, of the intent to apply for an extension.
(2) 
The city manager may grant an extension on a required cleaning frequency on a case-by-case basis where the user has demonstrated, with defensible analytical results, the specific trap will produce an effluent in consistent compliance with this article if such an extension is granted.
(3) 
The notification of intent to apply for an extension shall include:
(A) 
Facility information:
(i) 
The name and address of the facility;
(ii) 
The name and telephone number of the facility contact;
(iii) 
Normal business hours; and
(iv) 
The type of business;
(B) 
Treatment unit information:
(i) 
The type of treatment unit and the capacity in gallons;
(ii) 
A brief description of the treatment unit;
(iii) 
The time(s) of day the greatest hydraulic and organic loadings to the treatment unit normally occur;
(iv) 
The date of the most recent cleaning and inspection of the unit;
(v) 
A statement of the physical condition of the unit; and
(vi) 
Where applicable, the name of any treatment products used and a copy of the city manager’s approval letter for the use of the product;
(C) 
A proposed sampling schedule, including:
(i) 
The date(s) the user proposes to collect the samples;
(ii) 
The times each sample will be collected;
(iii) 
The name, telephone number and qualifications of the person who will collect the samples; and
(iv) 
The name and telephone number of the laboratory which will analyze the samples;
(D) 
Other information as may be requested by the city manager.
(4) 
The user shall obtain approval of the proposed sampling schedule prior to initiation of the sampling and analyses. The user shall certify the sampling schedule will be carried out as submitted or as approved. The city manager shall reserve the right to modify a sampling schedule as deemed necessary.
(5) 
The user shall be required to provide analytical results for not less than four (4) oil and grease analyses for samples collected during peak flow periods through the unit during the normal working hours of a twenty-four-hour period.
(A) 
Samples shall be collected at an approved sampling port and shall be collected by a qualified person properly trained in the collection and handling of wastewater samples.
(B) 
Samples shall be collected seventy (70) to seventy-five (75) days after the most recent cleaning.
(C) 
Samples shall be analyzed, separately, by a reputable laboratory using approved analytical procedures.
(D) 
The user shall submit a written request for a cleaning schedule extension, including:
(i) 
A copy of the cleaning and maintenance records for the treatment unit for the previous twelve (12) months; and
(ii) 
A copy of the laboratory analytical reports, including quality control data and appropriate chains of custody.
Incomplete or unverifiable results shall not be considered.
(6) 
The city manager may grant extensions to the cleaning schedule as follows:
(A) 
A thirty-day extension may be granted where the average oil and grease concentration of the analyses is less than seventy (70) percent of the concentration limit and no single concentration exceeded eighty (80) percent of the concentration limit.
(B) 
A sixty-day extension may be granted where the average oil and grease concentration of the analyses is less than fifty-five (55) percent of the concentration limit and no single concentration exceeded sixty-five (65) percent of the concentration limit.
(C) 
A ninety-day extension may be granted where the average oil and grease concentration of the analyses is less than forty (40) percent of the concentration limit and no single concentration exceeded fifty (50) percent of the concentration limit.
(D) 
In no case shall an extension greater than ninety (90) days be granted.
(7) 
Extensions granted shall begin on the date the samples for which results were submitted were collected as documented on the chain of custody.
(8) 
Where an extension has been granted, the unit shall consistently produce an effluent in compliance with the terms of this article or other applicable ordinances. The city manager shall reserve the right to collect and analyze samples of any user’s discharge and may revoke, without notice, any extension where the city manager believes it is in the best interest of the proper operation of the POTW.
(A) 
Where an extension has been granted and the results of any sample analysis exceed the oil and grease limitation by twenty-five (25) percent or more, the user shall immediately clean and inspect the trap and shall return to the original cleaning schedule. Where the user has been required to return to an original cleaning frequency, the user shall be required to submit a new request for extension if desired.
(B) 
Where an extension has been granted and the results of any sample analysis exceed the oil and grease limitation by any magnitude but less than twenty-five (25) percent, the user shall immediately clean and inspect the trap and shall increase the established cleaning frequency by at least thirty (30) days.
(C) 
Where an extension has been granted and the city must clean associated public sewer lines and the stoppage is traceable to or known or suspected to be caused by the user’s facility, the user shall immediately clean and inspect the trap and shall return to the original cleaning schedule. The user will be required to submit a new request for extension if desired.
(Ordinance 395, sec. 2, adopted 7/21/15)
(a) 
All fixtures with a potential to carry grease-bearing waste shall be plumbed to the grease trap. The first step in determining the appropriate size of the grease trap is to calculate the total number of fixture units connected to the trap. The following fixture unit counts shall be assigned to each different kind of fixture:
Kind of Fixture
Trap and Trap Arm Size
Fixture Units
3-compartment sink
1-1/2", 2"
3, 4
2-compartment sink
1-1/2"
2
Dishwasher
2"
4
Garbage grinder
2"
4
Wok stove
2"
4
Hand sink
–
0
Mop sink
–
0
Floor drains (2", 3", 4")
2", 3", 4"
2, 3, 4
Floor sinks (3", 4")
3", 4"
3, 4
Notes: Hand sinks and mop sinks are not required to be plumbed to the grease trap. For indirect waste systems where hub drains and floor sinks are used as receptors for dishwashers, 2-and 3-compartment sinks, etc., the fixture unit shall be twice (2x) the floor sink or hub drain fixture unit count. In such cases the fixture count for the indirect waste source is not counted.
(b) 
The next step is to determine the minimum flow rating of the grease trap. This is done by multiplying the total fixture unit count times three gallons/minute:
Grease trap flow rating = Total fixture unit count x 3 gallons/minute
(c) 
The minimum liquid holding capacity of the trap is calculated by multiplying the grease trap flow rating (in gallons per minutes) times twelve minutes:
Grease trap liquid holding capacity (gallons) = Grease trap flow rating x 12 minutes
(d) 
Facilities using dishwashers, wok stoves, or garbage grinders are required to install 2-compartment traps with a 12-minute total retention time.
(e) 
Upon approval from the city manager, fixtures receiving non-grease-bearing wastes may be drained through a grease trap, but shall not be included for grease trap sizing (i.e., condensate for coolers).
(Ordinance 395, sec. 2, adopted 7/21/15)
(a) 
The approved design for grease traps shall be as follows:
(1) 
The grease trap must be constructed in accordance with the current plumbing codes adopted by the city, as amended, and installed in a manner acceptable to the city manager (no exceptions).
(2) 
The grease trap shall have two compartments.
(3) 
While operating at the trap’s rated flow capacity, the first compartment must provide a retention time of no less than seven minutes, and the second compartment must provide a retention time of no less than five minutes, for a minimum total of twelve minutes.
(4) 
Trap inverts and vents shall be external to the compartments.
(5) 
The flow line to the trap (upstream of inlet invert) must be at least 3 inches above the static water level of the tank.
(6) 
Similarly, the trap vent must be at least 3 inches above the static water level of the tank.
(7) 
The trap inlet must be at least 24 inches below the static water level of the tank, and the trap outlet must be at least 12 inches above the floor of the tank.
(8) 
Adequate flow diffusion features must be provided to evenly distribute flow throughout the grease trap. Examples of such features would include a flow diverter plate in the primary compartment and “tee” piping on the tank outlet.
(9) 
Each trap compartment shall be accessible for cleaning and inspection purposes (no exceptions).
(b) 
Exceptions to certain of these criteria may be considered for approval in conjunction with the plan review process. In such cases, engineering drawings and supporting performance data must be submitted to and approved by the city manager or his designee prior to grease trap installation. Metal grease traps of alternative designs may be approved for those sites needing grease traps of 250 gallons or less.
(c) 
View a conceptual drawing of a typical grease trap design.
(d) 
View contact information for grease trap manufacturers that are familiar with these criteria. However, do not purchase any grease trap without first verifying with the city office that the specific model will be approved for installation.
(Ordinance 395, sec. 2, adopted 7/21/15)