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(a) No person shall discharge or cause to be discharged into a public sewer any of the following toxic pollutants in excess of the pollutant concentration in the water supply delivered to his or her premises, unless the person is issued a wastewater discharge permit by the Safety-Service Director, which permit allows the discharge of increased amounts of such pollutants. The discharge of such pollutants allowed by the permit shall not exceed the following maximum daily concentrations:
Maximum Daily Concentration (mg/l)
(1) Any and all industrial and commercial users of the publicly owned treatment works (POTW) shall take all steps necessary to eliminate mercury from their discharges, and at no time shall exceed the concentration limit of 0.000152 mg/L (or 152 ng/L.)
(2) The defined set of Best Management Practices (BMPs) for dental offices shall be as follows:
A. Eliminate all use of elemental mercury. Use only pre-capsulated amalgam.
B. Any unused elemental mercury still on hand must be recycled through an approved recycling facility.
C. Limit the amount of amalgam used to the smallest appropriate size for each restoration. Keep a variety of capsule sizes on hand.
D. Use chair-side traps to retain amalgam. Change or clean the chair-side traps frequently as per the manufacturer’s recommendations. Flush the vacuum before changing. Do not rinse chair-side traps into a sink drain or place them in the biohazard containers. Use a log sheet to document when chair-side traps are cleaned and replaced.
E. Change or clean vacuum pump filters and screens frequently or as per the manufacturer’s recommendations. Do not rinse vacuum pump filters and screens into a sink drain or place them in the biohazard containers. Use a log sheet to document when vacuum pump filters and screens are changed or cleaned.
F. Amalgam waste must be either recycled (preferred) or hauled away as a hazardous waste. Amalgam waste must not be put in the trash, with infectious waste, or down the drain. Amalgam waste includes:
1. Non-contact amalgam (scrap), the excess mix leftover at the end of a dental procedure.
2. Contact amalgam that has been in contact with the patient. (Examples are extracted teeth with amalgam restorations or amalgam captured by chair- side traps, filters or screens.)
3. Amalgam waste captured in chair-side traps. (Traps from dental units dedicated strictly to hygiene may be placed in with regular garbage.)
4. Vacuum pump filters or traps containing amalgam sludge and water.
5. Amalgam sludge, the mixture of liquid and solid material cleaned from vacuum pumps filters and other amalgam capture devices.
6. Empty amalgam capsules leftover from the pre-encapsulated dental amalgam.
G. Store amalgam waste in a covered, segregated, and clearly labeled airtight plastic container, or per your recycler’s instructions.
H. Document all amalgam waste recycling or disposal. Keep all such records on file for a minimum of three years. Records should include a description of the materials recycled or disposed of; dates of recycling or disposal; name, address and phone number of the recycling or disposal company.
I. Train all staff who may handle mercury-containing material in its proper use and disposal.
J. Maximize the use of high speed suction (vacuum) system because it captures more waste than the coarse screens in the cuspidor.
K. Avoid using sodium hypochlorite (bleach) to disinfect the vacuum lines because it dissolves mercury out of the amalgam.
L. According to the Naval Institute for Biomedical and Dental Research, the following is a list of some of the line cleaners that do not appear to dissolve mercury from amalgam and are alternative disinfectants to bleach:
3. Super Dent;
4. Evacuation Cleaner ProE-Vac;
5. Turbo Vac Line Flush;
8. Vacu Cleanse;
9. Gobble Plus;
10. Sani-Treat Plus;
12. Green and Clean;
M. Post these Best Management Practices in the office where they will be available for frequent reference by the staff.
N. Dental offices that are unable to meet the concentration limit of 152ng/L shall install and maintain, at their own expense, an amalgam separator on the sanitary line prior to discharge. The collected amalgam waste shall be properly recycled in accordance with all local, State, and Federal regulations.
(3) Any and all industrial and commercial users of the City sanitary sewer shall take all steps necessary to eliminate silver from their discharges. The minimum BMPs for a facility known to have the potential to discharge measurable concentrations of silver in the wastewater discharge shall be to install and maintain, at the users expense, a silver recovery unit. The user shall recycle the collected silver in accordance with the local, State, and Federal regulation.
(4) The following load limits to the wastewater treatment plant are set forth, in pounds per day, to reflect the maximum amount that the City can allocate to industry for each parameter:
Maximum Allocations to
Industrial Users (lbs/day)
The City shall not exceed these load limits when permitting industrial users. The City can, whenever the City determines it is necessary, make adjustments with the current industrial user permits provided the above load limits are not exceeded.
(b) (1) No person shall discharge, or cause to be discharged, wastewater which exceeds the maximum daily concentrations established for the following compatible pollutants, without permission from the Safety-Service Director and payment of the appropriate surcharge. Permission to exceed the limits for the following pollutants will only be granted and for only so long as the loadings to the wastewater treatment plant do not exceed design loadings or cause problems within the collection system or at the wastewater treatment plant.
Oil & Grease
Phosphate (as P)
(2) In accordance with the local limits justification study of October 2008, the City shall not allocate, to the total of industrial users, compatible pollutants limits which would exceed the following total loadings to the wastewater plant, in pounds per day:
Maximum Allocation To Industrial Users (lbs/day)
Oil & Grease
Phosphate (as P)
(3) Total Dissolved Solids (TDS) Best Management Practices (BMPs): All industrial and commercial users of the City sanitary sewer shall take all steps necessary to limit the amount of total dissolved solids (TDS) in their wastewater discharges and shall strive for a target value of 9,473 mg/L.
(c) Best Management Practices (BMPs) may be used in lieu of numerical limits as deemed necessary by the Water Pollution Control Board in accordance with Ohio EPA Pretreatment Guidance The Use of Best Management Practices (BMPs) as Industrial Local Pretreatment Limits, as amended, provided however, that the use of BMPs does not cause problems in the sewer collection system or at the wastewater treatment plant.
(d) Except where expressly authorized to do so by an applicable pretreatment standard or requirement, no industrial user shall ever increase the use of process water, or in any other way attempt to dilute a discharge as a partial or complete substitute for adequate treatment to achieve compliance with a pretreatment standard or requirement. The City may impose mass limitations on industrial users who or which are using dilution to meet applicable Pretreatment Standards or requirements, or in other cases where the imposition of mass limitations is appropriate.
(e) Grease, oil and sand interceptors or traps shall be provided when they are necessary for the proper handling of liquid wastes containing grease in excessive amounts, sand and other harmful ingredients, except that such interceptors or traps shall not be required for private living quarters or dwelling units. All interceptors or traps shall be of a type and capacity approved by the Safety- Service Director and shall be located as to be readily and easily accessible for cleaning and inspection. Grease and oil interceptors or traps shall be constructed of impervious materials 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 watertight. Where installed, all grease, oil and sand interceptors or traps shall be inspected, cleaned out and maintained by the owner, at his or her expense, with a frequency that will prevent oil, grease and sand from entering the sanitary sewer. Receipts from the clean out and proper disposal of oil, grease and sand from the interceptors or traps shall be kept on file on the premises and made available to the City upon request for inspection. Where grease, oil and sand interceptors are installed, a sampling manhole may be required to be installed, at the owner’s expense, on the sanitary lateral between the building and the lateral connection to the City sanitary sewer to allow for the sampling of the wastewater discharge if necessary.
(f) New sources shall install and have in operating condition, and shall start up all pollution control equipment required to meet all applicable local limits and other provisions of this chapter prior to beginning discharge. Within the shortest feasible time (not to exceed 30 days), new sources shall meet all applicable pretreatment standards.
(Ord. 2002-46. Passed 3-4-02; Ord. 2003-24. Passed 2-3-03; Ord. 2009-126. Passed 5-18-09; Ord. 2011-72. Passed 6-6-11; Ord. 2011-166. Passed 10-17-11.)