Township of Cranberry, PA PRETREATMENT OF WASTEWATER

[Ord. No. 2020-498, 9/24/2020]

The following pretreatment measures, as deemed necessary by the Township, as part of a user's initial pretreatment facilities, changes in pretreatment facilities, or methods of operation are necessary to protect the POTW and user compliance with this chapter.

Modify flow including; restricting user discharge during peak flow periods, designate that certain wastewater be discharged only into specific sewers, relocate point of discharge, consolidate points of discharge, and separate nonindustrial waste streams from industrial waste streams and such other conditions as may be necessary to protect the POTW and determine the user's compliance with the requirements of this chapter.

Require any user discharging into the POTW to install and maintain, at user expense, a suitable storage and flow control facility to ensure equalization of flow.

User(s) with the potential to discharge flammable substances may be required to install and maintain an approved combustible gas detection meter.

Pretreatment facilities shall be capable of producing an effluent with an oil and grease concentration which, alone or in conjunction with a discharge or discharges from other sources, will not cause obstruction, interference or other problems in the POTW and shall be installed and maintained such that excessive amounts of oil and grease, grit, sand, and inert solids are effectively prevented from entering the POTW as follows:

Grease interceptors and or grease traps shall be provided by food service facilities when, deemed necessary by the Township for the proper handling of wastewater containing excessive amounts of fats, oil and grease.

Oil and grit separators (also known as "oil/water separators") shall be provided by facilities including car washes, fueling stations, and commercial garages, for the proper handling of wastewater containing excessive amounts of grit, sand, or petroleum-based (non-polar) oils and grease.

FOG control equipment shall not be required for residential user(s) including; single-family residences, duplexes, or apartment complexes, unless deemed necessary by the Township.

Toilets, urinals, and other similar fixtures shall not discharge through grease interceptors, grease traps, or oil/water separators.

Unless written waiver is granted by the Township, all new food service facility establishments, including preexisting construction or new construction, are required to meet the following requirements. Kitchen fixtures including three bowl sinks, pre-rinse sinks, prep sinks, mop sinks, and floor drains must be connected to the grease trap. If a dishwasher is present without a pre-rinse sink, it is required to be connected to the grease trap. If both a dishwasher and pre-rinse sink are present, the dishwasher effluent flow shall be separated from the grease trap. If there is a grease interceptor present, all fixtures, including the dishwasher, shall be connected to the grease interceptor. Upon verification that an existing food service facility does not meet the requirements above, the Township may require the plumbing to be altered, in which case, all costs of alterations shall be incurred by the food service facility; the user shall specify in writing to the Township a schedule for completion of work within 30 days of the Townships notification to the user or within an alternative time frame set forth by the Township.

Grease interceptors and oil and grit separators shall contain < 25% or 1/4 of the total volume of liquid with combined fats, oil, grease, and solids at any given time. Grease traps shall hold less than the highest rated capacity of FOG as specified on their cut sheets. The Township determines grease trap capacity compliance using the current approved methodology.

Grease interceptors, grease traps, oil and grit separators and the associated plumbing design shall be so located to be safe and easily accessible for cleaning and inspection.

The size of grease interceptors, grease traps and oil/grit separators are determined initially by the User using the Townships provided calculation method. The user shall submit, for the Township's approval, cut sheets indicating that the calculated size complies with Township requirements. The Township must approve the cut sheets prior to the installment of any FOG devices.

Grease traps shall have a minimum flow rating of 50 gpm and a FOG retention size of 100 pounds, unless the user secures a written variance from the Township.

Grease interceptors and oil and grit separators shall have a 500-gallon minimum liquid capacity, unless the user secures a written variance from the Township.

Grease interceptors, grease traps, and oil and grit separators must contain all elements listed in the Township's public and private improvements code. Grease interceptors or oil and grit separators with sampling manholes are required to pass a vacuum test prior to the devices use. The contractor shall provide a minimum of 48 hours' notice to the Township of the contractors intent to perform any sanitary sewer testing. All sampling manholes shall be tested. Testing shall be in accordance with ASTM C1244, standard test method for concrete sewer manholes by the negative air pressure (vacuum) test. Sampling manholes shall be tested after the manhole has been assembled but prior to backfill of the grease device. The casting frame/top and all added risers shall be tested. No standing water shall be allowed in grease interceptors or oil and grit separator while the test is occurring. All pipes, manhole boots, stub-outs, and other openings shall be suitably plugged in such a manner to prevent displacement of the plugs while the vacuum is drawn. Installation and operation of the vacuum equipment and indicating devices shall be in accordance with the equipment specifications and instructions provided by the manufacturer. A vacuum of 10 inches of mercury (Hg) shall be drawn on the manhole. After which, the vacuum pump shall be shut off. If the indicated vacuum pressure drops to nine inches in less than one minute, the test apparatus shall be removed and the appropriate repair(s) shall be performed. The result of the test is considered be failed until a time period of one minute occurs before the vacuum pressure drops one inch. "Appropriate repairs" is defined as sealing the grade rings and inside joints with an epoxy compound or approved equivalent.

Grease interceptors as well as oil and grit separators with a liquid capacity greater than 100 gallons are required to pass a vacuum test.

Pretreatment facilities shall be inspected, cleaned, and repaired regularly, as needed, by the user at the user's expense. The Township has the authority to assign a required cleaning frequency for grease interceptors, grease traps, and oil and grit interceptors at the user's expense. The user is required to abide by the assigned cleaning frequency and participate in record tracking methods as required by the Township.

Each facility is responsible for the cost and scheduling of repairs to or replacement of its FOG pretreatment including grease interceptors, grease traps, and/or oil/water separators. Users are required to obtain building permits where required.

Failure of the user to properly design, size, install, operate or maintain FOG pretreatment requirements is in violation of this chapter.

Dental dischargers (DDs) must meet the requirements spelled out in EPA's Dental Office Category, 40 CFR Part 441. DDs that place or remove amalgam fillings shall install an amalgam separator for the proper handling of wastewater containing dental amalgam. Amalgam separators and associated plumbing design shall be approved by the Township and located to be safe and easily accessible for cleaning and inspection. The size, determined by the user, of the amalgam separator must accommodate the maximum discharge rate of amalgam process wastewater. In the event that an amalgam separator is not functioning properly, the amalgam separator must be repaired per the manufacturer instructions or replaced with a unit that meets the requirements no later than 10 business days after the malfunction is discovered by either the DD, an agent or representative of the DD or the Township. The Township may implement required recordkeeping or amalgam separator cleaning frequency for DDs.

The Township may require user(s) to install pretreatment devices to meet the needs of this chapter. If it is determined that a user must install a pretreatment device, the Township may choose to place the user under a wastewater permit.

The Township may identify existing wastewater pretreatment devices, technology, or general equipment as needing constructive maintenance or replacement when in the opinion of the Township it has failed to be maintained, it has reached the end of its usable life, or it is not meeting the pretreatment requirements of this chapter. If in the opinion of the Township, maintenance or replacement of the aforementioned equipment is required, the user shall specify in writing to the Township a schedule for completion of work within 30 days of the Townships notification to the user or within an alternative time frame set forth by the Township. In the case that constructive maintenance or replacement requirements are in order, the user shall, at a minimum, maintain or replace the item(s) with equivalent pretreatment parts or devices. If applicable, maintenance of existing pretreatment items shall be completed using the recommendations of the maintenance manuals. Constructive maintenance and replacement items as well as any demolition and installment plans shall be submitted by the user and approved by the Township prior to installment. All costs associated with constructive maintenance or replacement shall be incurred by the user.