November 25, 2009 > City's sewer use ordinance amendment introduced
City's sewer use ordinance amendment introduced
Wastes from dentists and restaurants to be regulated more
By Dustin Findley
Principal Engineer Kathleen Phalen presented to council amendments to the City's sewer use ordinance.
Phalen explained that the purpose of this ordinance is to support the creation of a dental mercury amalgam (for fillings) capture program and to revise the existing requirements the City has for disposal of fats, oil and grease to the City sewer system.
Dental waste turns out to be one of the largest sources of mercury to the wastewater waste stream.
The regional water quality control board, a state regulatory agency, has, in 2007, passed an order stating that they would control it throughout the Bay Area. They are phasing it into all the wastewater treatment plants that discharge to the bay of the Bay Area as each plants five-year discharge program comes up for renewal.
In the case of the San Jose and Santa Clara Water Pollution Control Plant, which is the plant that Milpitas sends its wastewater to, has been informed that it must implement this dental program in the year 2010.
Because the master agreement requires that Milpitas revise its ordinance to support the San Jose program, Milpitas was required to amend its sewer use ordinance and are required to participate in this program.
Separated mercury dental fillings have to be treated as hazardous wastes. Wastes and sludge from the drilling of teeth and so forth has not been fully captured to date, getting into the sewage system via the chair-side traps that dental offices have.
What the dental mercury amalgam program will require is that dentists who remove or place mercury amalgam fillings will have to apply for a five year permit from the San Jose treatment plant, install an amalgam separator, implement mercury reduction best management practices, and submit an annual compliance report to the San Jose treatment plant staff.
The cost of an amalgam separator is around $752,000, intercepting the waste stream from the chair side traps.
Mercury reduction best management practices include maintenance of the traps and other items such as staff training and correct material storage. The cost of which is estimated at $300 a year.
Dentists who do not place fillings are excluded.
San Jose treatment staff will send out notices of workshops for dentists in January. They are planning on having a workshop in Milpitas on January 22. In February they will mail out permit applications, which will be due in March.
Dentists will be required to install their amalgam separators by July, and submit their application for certification from October to December 2010.
The City already has fats, oil and grease rules in its municipal code. The amendment revises the language.
The City adopted a sewer system management plan this summer that included fats, oils and grease control component, as required by State law.
Problems with fats, oils and grease in the sewers is that they can cause back ups into residences and businesses, and require city maintenance crews to perform additional sewer flushing and cleaning.
The revisions seek to improve the definition and revise the installation, cleaning, and maintenance requirements for grease removal devices or grease traps to make sure businesses, such as restaurants, are meeting requirements.
The revisions add additional requirements for these businesses to keep records of their maintenance of these units.
All the cities that use the San Jose treatment plant will be under the same program as Milpitas.
The order came from the San Francisco Bay Regional Water Quality Control Board and applies to all treatment plants that discharge directly to the bay.
San Francisco Public Utilities Commission, East Bay Municipal Utilities Division, Palo Alto, Central Contra Costa have already implemented the program.
Ultimately, the authority for these regulations come from the federal Clean Water Act and the regulations implementing that act come through the US Environmental Protection Agency (EPA).
Council voted to introduce the ordinance. Staff will bring it back to council for adoption on December 1 and it will go into effect 30 days later.