Chapter 15.48 — SEWER USE AND SOURCE CONTROL REGULATIONS

Wastewater may be discharged into community sewers for collection, treatment, and disposal by the POTW;

provided, that such wastewater discharge is in full compliance with this part (Chapters 15.44 through 15.76), local

limits and the conditions of any wastewater discharge permit; and further provided, that the user pays all

applicable city sewer fees and charges including any penalties or charges assessed under this part. (Ord. 2282 NCS

§3, 2007.)

A. No user shall contribute or cause to be contributed any pollutant or wastewater which will pass through the

city’s facilities or cause or contribute to interference with the operation of performance of the city’s facilities. Any

violation of the terms of this part, local limits or a wastewater discharge permit is prohibited and shall constitute

interference. This prohibition includes any type of pollutants or wastewater as set forth in the prohibition sections

of this part. These general prohibitions apply to all users of the city’s facilities whether or not the user is subject to

national pretreatment standards or any other national, state, or local pretreatment standards or requirements.

B. A user shall not introduce into the POTW any of the pollutant(s) which cause:

 1.  A violation of the POTW’s NPDES permit or a deterioration of water quality in the receiving stream; or a

 violation of the POTW’s general water reuse permit;

 2.   Pass through or interference;

 3.   Restrict sludge disposal options or cause a violation of sludge disposal regulations;

 4.  Endanger the health and safety of the POTW collection systems employees, POTW employees or the

general public.

C. A7rmative Defenses. A user shall have an aYrmative defense in any action brought against it alleging a

violation of the general prohibitions established in 40 CFR 403.5(b)(4) if the user can demonstrate that both of the

conditions below from 40 CFR 403.5(a)(2) are met:

 1.   User did not know or have reason to know that its discharge, alone or in conjunction with a discharge or

discharges from other sources, would cause pass through or interference.

 2.   Directly prior to and during the pass through or interference, the user was in compliance with the

 existing limits for each pollutant in its discharge, or if there were no such existing limits, the user’s discharge

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 directly prior to and during the violation did not change substantially in nature or constituents from the user’s

 prior discharge activity when the city was regularly in compliance with its NPDES permit requirements, and

with other applicable requirements for POTW operations including sewage sludge use and disposal.

(Ord. 2282 NCS §3, 2007.)

In addition, a user shall not introduce any of the following pollutants into the POTW:

A. High Temperature. Heat in amounts which may inhibit biological activity in the POTW resulting in interference,

but in no case heat in such quantities that the temperature at the POTW treatment plant exceeds forty degrees

centigrade (one hundred four degrees Fahrenheit) unless the approval authority, upon request of the POTW,

approves alternate temperature limits.

B. Pollutants which cause corrosive structural damage to the POTW, but in no case discharges with a pH lower

than 5.0 or higher than 10.5, or having a pH which will cause damage to the collection system or interfere with

POTW treatment processes.

C. Pollutants which create a Wre or explosion hazard in the POTW, including, but not limited to, waste streams

with a closed cup Xashpoint of less than one hundred forty degrees Fahrenheit or sixty degrees centigrade using

the test methods speciWed in 40 CFR 261.21. Any liquids, solids or gases which by reason of their nature or

quantity are or may be suYcient either alone or by interaction with other substances to cause a Wre or explosion

or endanger public safety or interfere with the operation of the POTW.

At no time shall two successive readings on an explosion hazard meter, at the point of discharge into the sanitary

sewer (or at any point in the system), be more than Wve percent or any single reading over ten percent of the lower

explosive limit (L.E.L.) of the meter, or have a closed-cup Xash point of less than one hundred forty degrees

Fahrenheit or sixty degrees centigrade using the test methods speciWed in 40 CFR 261.21. Prohibited materials

include but are not limited to gasoline, kerosene, naphtha, benzene, toluene, xylene, ethers, alcohols, ketones,

aldehydes, peroxides, chlorates, perchlorates, bromates, carbides, hydrides and sulWdes and any other substances

which the city, the state and EPA has identiWed as a Wre hazard or a hazard to the system.

D. Obstruction of Flow. Solids or viscous pollutants in amounts which will cause obstruction to the Xow in a

community sewer or in the POTW resulting in interference. Items such as but not limited to grease, garbage with

particles greater than one-half inch (one and twenty-seven hundredths centimeters) in any dimension, animal guts

or tissues, paunch manure, bones, hair, hides, Xeshing, entrails, whole blood, feathers, ashes, cinders, wax, sand,

spent lime, stone or marble dust, metal, glass, straw, shavings, grass clippings, rags, spent grains, spent hops,

waste paper, wood, plastics, tar, asphalt residues, residues from reWning or processing of fuel or lubrication oil,

mud or glass grinding or polishing wastes.

E. Toxic Pollutants. Any wastewater containing toxic pollutants in suYcient quantity, either singly or in interaction

with other pollutants, that would pass through or cause interference with the wastewater treatment process, or

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constitute a hazard to human, animal or plant life, including aquatic organisms, or create any hazards in the

waters receiving the wastewater treatment plant eZuent.

A toxic pollutant shall include but not be limited to any pollutant identiWed pursuant to Section 307(a) of the Act

and the California Toxics Rule. Compounds speciWcally prohibited include any polychlorinated biphenyl (PCB), any

pesticide (including any insecticides, herbicides, or fungicides) such as but not limited to chlordane, heptachlor,

heptachlor epoxide, aldrin, dieldrin, dichlorodiphenyl trichloro ethane (DDT), dichloro-diphenyldichloro ethene

(DDE), and rothane (DPD).

F. Noxious or Malodorous Substances. Any harmful or o[ensive gases or solids which either singly or by

interaction with other wastes are suYcient to violate or have the potential to cause violations of air quality

standards at the POTW or in community sewers, create a public nuisance or hazard to life or are suYcient to

prevent entry into the sewers for maintenance and repair. Any volatile organic pollutant in such concentration that

it has the potential to cause the headspace gases to exceed a three hundred hexane equivalent level over

equilibrated wastewater or exceed toxicity discharge screening levels based on fume toxicity.

G. Disposal/Reclamation. Any substance which may cause the POTW’s eZuent or any other product of the

POTW, such as residues, sludges, or scums, to be unsuitable for reclamation and reuse or to interfere with the

reclamation process. In no case shall a substance discharged to the POTW cause a violation of the criteria,

guidelines or regulations developed under Section 405 of the Act; any criteria, guidelines or regulations a[ecting

sludge use or disposal developed pursuant to the Solid Waste Disposal Act, the Clean Air Act, the Toxic Substances

Control Act, or state or local criteria applicable to the sludge disposal.

H. POTW Violation. Any pollutant including oxygen demanding pollutants (BOD, etc.) causing the POTW to violate

or continue to violate its NPDES permit. This includes but is not limited to slug discharges, oxygen demanding

pollutants (BOD or COD), suspended solids, pH, heavy metals, oil and greases or toxic organic compounds;

released in a discharge at a Xow rate and/or pollutant concentration which will cause interference with the POTW.

I. Detrimental Environmental Impact. Any substance which may have a harmful environmental impact or create a

nuisance in the waters of the state or a condition which violates the rules and regulations of any public agency

having regulatory jurisdiction over the city, including but not limited to any statute or any rule, regulation, or

requirement of any public agency or state or federal regulatory body.

J. Discoloration. Any wastewater creating discoloration or any other condition in the quality of the POTW eZuent

such that receiving water quality requirements established by law cannot be met.

K. Hazard or Public Nuisance. Any waste which, as determined by the city, may have an adverse or harmful e[ect

on sewer, maintenance personnel, wastewater treatment plant personnel or equipment, treatment plant eZuent

quality, public or private property or may otherwise endanger the public, the local environment or create a public

nuisance. The city shall, in determining the acceptability of speciWc wastes, consider the nature of the waste and

the adequacy of the collection, treatment and disposal system available to accept the waste.

L. Excessive Flow. Total quantities of Xow or instantaneous peaks which due to volume or manner of delivery

require a disproportionate share of the city’s treatment plant capacity. This also includes Xows which, alone or in

combination with others, cause excessive treatment costs and/or treatment plant process upsets.

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M. Radioactive Wastes. No user shall, and it shall be unlawful to, discharge, cause to be discharged, or permit to

be discharged, any radioactive waste into the sanitary sewer, except:

 1.   Users authorized to use radioactive materials by the State Department of Health or other governmental

agency empowered to regulate the use of radioactive materials may discharge, cause to be discharged,

permit to be discharged such wastes; provided, that such wastes are discharged in strict conformance with

the current State of California Code of Regulations Title 17 and federal regulations and recommendations for

 safe disposal of such wastes as they now exist or may hereafter be amended.

 2.  The user so acting does so in compliance with all applicable rules and regulations of all other regulatory

agencies having jurisdiction over such discharges.

N. Petroleum oil, nonbiodegradable cutting oil, or products of mineral oil origin in amounts that will cause

interference or pass through.

O. Pollutants which result in the presence of toxic gases, vapors, or fumes within the POTW in a quantity that

may cause acute worker health and safety problems.

P. Any trucked or hauled pollutants, except at discharge points designated by the POTW.

Q. Any sewage not amenable to treatment as this term is deWned herein with the use of the facilities and

treatment processes employed by the city at the time of the discharge.

(Ord. 2282 NCS §3, 2007.)

These limits shall be deemed pretreatment standards for the purposes of Section 307(d) of the Act.

A. No person shall discharge wastewater containing in excess of:

                                   Discharge Limitations

                                        DAILY COMPOSITE SAMPLE
                POLLUTANT
                                                    (values in mg/L)

                  Arsenic                                    0.20

               Barium                                    7.00

                  Beryllium                                  0.03

            Cadmium                                 0.01

               Chromium—(Total)                        0.42

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                                   Discharge Limitations

                                        DAILY COMPOSITE SAMPLE
                POLLUTANT
                                                    (values in mg/L)

               Copper                                    0.34

                Cyanide                                   0.26

               Lead                                      0.12

               Mercury                                 0.001

                   Nickel                                     0.21

                Selenium                                  0.10

                     Silver                                     0.10

                  Zinc                                       1.00

B. Any discharge which contains greater than two thousand mg/L of suspended solids or one thousand Wve

hundred mg/L BOD, except discharges containing greater amounts of suspended solids and/or BOD that are

subject to a discharge permit that permits such greater amounts of suspended solids and/or BOD.

C. Any water or waste which contains more than one hundred mg/L, by weight, of oil or grease of petroleum

origin or fat, oil or grease of animal or vegetable origin, or which contains grease or oil or other substances that

will solidify or become viscous at temperatures between thirty-two to one hundred forty degrees Fahrenheit (zero

to sixty degrees centigrade).

D. Any waste containing total toxic organics (TTO) greater than one mg/L. TTO is deWned as the sum of the

individual constituent concentrations from EPA Methods 624 and 625.

E. The city authority may impose equivalent mass-based discharge limitations in place of, or in addition to,

concentration-based discharge limitations in cases where the imposition of mass-based discharge limitations are

deemed appropriate by the city authority.

F. The discharge of wastewater containing items listed in Section 15.48.030(A) through (Q) or any other

compound in excess of concentrations found in typical domestic sewage. If an abnormal sewage surcharge is

levied as deWned in Section 15.44.020(A)(1) and (2), the city authority may impose an alternate discharge limitation

for the compound for which an average sewage surcharge has been levied.

(Ord. 2896 NCS §3, 2024; Ord. 2472 NCS §2, 2013; Ord. 2282 NCS §3, 2007.)

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It shall be unlawful to discharge any waste or wastewater into any storm drain or natural outlet unless the user

has obtained an NPDES permit and the user is in compliance with all applicable rules and regulations of all

agencies having jurisdiction over such discharge. (Ord. 2282 NCS §3, 2007.)

Stormwater, ground water, rain water, street drainage, subsurface drainage or yard drainage shall not be

discharged through direct or indirect connections to the sanitary sewer. The city may approve the discharge of

such water only when no reasonable alternative method of disposal is available. If a permit is granted for the

discharge of such water into the sanitary sewer, the user shall pay the applicable user charges and fees and meet

such other conditions as required by the city. (Ord. 2282 NCS §3, 2007.)

Unpolluted water including but not limited to cooling water, process water or blow-down from cooling towers or

evaporative coolers shall not be discharged through direct or indirect connection to a city sewer unless a permit is

issued. The city may approve the discharge of such only when no reasonable alternative is available.

If a permit is granted for the discharge of such water into a community sewer, the user shall pay the applicable

charges and fees and shall meet such other conditions as required by the city. (Ord. 2282 NCS §3, 2007.)

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 requirement.

The city may impose mass limitations on industrial users which are using dilution to meet applicable pretreatment

standards or requirements, or in other cases where the imposition of mass limitations is appropriate. (Ord. 2282

NCS §3, 2007.)

No user shall discharge any substance directly into a manhole, clean out or other opening in a sanitary sewer

other than through an approved building sewer, unless upon written application by the user and payment of the

applicable user charges and fees, the city issues a permit for such direct discharges.

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No person shall discharge any holding tank wastes, or wastes from barrels, storage tanks or any other such

containers not directly connected to the city sewer unless the user has obtained a special discharge permit. Unless

otherwise allowed by the city, under the terms and conditions of the special discharge permit, a separate permit

must be secured for each separate discharge. The user may be required to sample, analyze and report to the city

the characteristics of the waste, prior to the issuance of the permit. The permit may stipulate the speciWc location

of the discharge, the time of day the discharge is to occur, limits of the volume discharged and the constituents

and characteristics of the waste. The user shall pay all applicable charges and fees and shall meet such other

conditions as required by the city. (Ord. 2282 NCS §3, 2007.)

Waste from garbage grinders may be prohibited by the city from being discharged into the sanitary sewer except:

A. Waste from residential premises generated in the preparation of food.

B. Where the user has an existing garbage grinder and has a permit for that speciWc use from the city.

At any time the property or business changes ownership, excluding residential property, the city may require that

the existing garbage grinders on the property be removed. Garbage grinders shall not be used for grinding plastic

or paper products, inert materials, or garden refuse. (Ord. 2282 NCS §3, 2007.)

All new gasoline Wlling stations, garages, self-service automobile washers, autobody facilities, and other public

wash racks where vehicles are washed shall install catch basins in conformity with the plumbing code in

accordance with a permit obtained from the building oYcial. In the event any existing premises do not have a

catch basin and the sewer line servicing the facility stops up due to grit or slime in the sewer lines, then the owner

or operator of such premises shall be required to modify these facilities to construct a catch basin as a condition

of continuing use of the system. No stormwater shall be diverted to these catch basins. No wash rack waste shall

be diverted into the stormwater system. See also the requirements for vehicle wash facilities contained in Section

15.17.040. (Ord. 2472 NCS §2, 2013; Ord. 2282 NCS §3, 2007.)

Hospitals, clinics, oYces of medical doctors, and convalescent homes shall not discharge to the sanitary sewer any

medical wastes. (Ord. 2282 NCS §3, 2007.)

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Fat, grease, grit, oil, lint, and sand removal devices (interceptors and grease traps) shall be installed by the user

when it is determined by the city that such device is necessary for the proper handling of liquid wastes containing

grease, fat, grit, oil, lint, sand or other harmful ingredients which accumulate and cause or threaten to cause

stoppage or impair the eYciency of the sewers, wastewater plant or the safety of the city employees, except that

such removal devices shall not be required for residential units. Grease removal devices are required at all food

service establishments. A food service establishment is any commercial facility discharging kitchen or food

preparation wastewater including, but not limited to, restaurants, fast food establishments, delicatessens,

caterers, bakeries, donut shops, halls and auditoriums with kitchens, and any other businesses that perform on-

site cooking or food preparation.

All removal devices shall be of a type and capacity approved by the division of water resources and conservation

and compliant with Uniform Plumbing Code. The user shall pay the applicable charges and fees and meet such

other conditions as required by the POTW prior to installation. The removal device shall be installed in conformity

with approved plans and in accordance with all applicable codes and regulations. The removal device shall be

located so as to be readily and easily accessible for cleaning and inspection. No device shall be installed in a food

preparation area.

Minimum grease removal device sizing criteria for new and modiWed kitchens:

A. Exterior in-ground grease interceptors are required for any food establishment with greater than nine

drainage Wxture units within the kitchen. The grease interceptor shall be a two-stage grease interceptor with a

minimum capacity of one thousand gallons. A larger grease interceptor(s) may be required based on the total

amount of drainage Wxture units as per the most current Uniform Plumbing Code.

B. Hydro-mechanical grease interceptors or grease traps are required for any food establishment with less than

nine drainage Wxture units within the kitchen. A minimum grease trap size of Wfty/one hundred equipped with a

Xow control valve is required or an equivalent grease removal device that is approved by the Plumbing and

Drainage Institute (PDI) may be considered. If two or more signiWcant drainage Wxtures cannot be plumbed into

one grease trap, then each separate Wxture will be plumbed to a separate grease trap. A larger grease trap(s) may

be required based on total amount of drainage Wxture units as per the most current Uniform Plumbing Code.

A vent is required to be installed downstream of any interior grease trap in accordance with the Uniform Plumbing

Code.

C. The following connections are restricted and/or prohibited:

 1.  Garbage grinders (disposals), except in the case where a one-thousand-gallon grease interceptor (or

 larger) is in use.

 2.   Dishwashers, except in the case where a one-thousand-gallon grease interceptor (or larger) is in use.

3. Toilets, urinals, wash basins or any Wxtures receiving fecal material shall not Xow through the grease

removal device.

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                         Table A.  DRAINAGE FIXTURE UNIT VALUES

    Type of Kitchen Fixture             Trap and Trap Arm Size              Fixture Units

Hand sink NA 0

Prep 1-compartment sink 1-1/2-inch 3

2-compartment sink 1-1/2-inch 3

3-compartment sink 1-1/2-inch 3

3-compartment sink 2-inch 4

3-compartment sink 3-inch 6

Mop sink 2- or 3-inch 3

Wok stove drain 2-inch 4

Dishwasher 2-inch 4

Floor drains                                                  2-, 3- or 4-inch                          2, 3 or 4

Floor sinks                                             3- or 4-inch                     3 or 4

Notes:

1. Hand sinks are not required to be plumbed to any grease removal device.

2. Prep sinks, mop sinks and Xoor drains may be required to be connected to a grease removal device at

the discretion of the city.

3. "Trap arm" is the portion of the Wxture drain between a trap and the vent.

4. Any dishwasher connection to a grease removal device will require a minimum one-thousand-gallon

gravity or exterior interceptor.

5. For any indirect waste systems where hub drains and Xoor sinks are used as a receptor for dishwashers,

two- and three-compartment sinks, or other similar Wxtures, the drainage Wxture unit count shall be twice

the Xoor sink or hub drain Wxture unit count and the drainage Wxture unit count for the indirect waste

source is not counted.

The removal device shall be maintained in eYcient operating condition by periodic removal of accumulated

grease, fat, grit, oil, lint, sand or other material. Failure to clean or maintain the removal device shall be a violation

and subject to an enforcement action as stated in city codes and regulations. Wastewater having excessive

temperatures (from dishwashers for example) causing the pass through of grease, shall not be discharged to the

removal device. No emulsiWers, enzymes, solvents or any other substances which cause the pass through of

grease shall be used in the removal device. Removal devices shall be located upstream of any dishwashers or

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discharges exceeding one hundred ten degrees Fahrenheit. Users requiring removal devices shall maintain

records of maintenance and cleaning of removal devices for three years. These records shall be made available to

the city for inspection and copying upon request.

Abandoned grease, fat, grit, oil, lint or sand removal devices shall be removed as required for abandoned septic

tanks (Uniform Plumbing Code) within thirty calendar days of cessation of business. All costs related to the

installation or removal of the devices shall be the responsibility of the user or property owner.

(Ord. 2402 NCS §2, 2011; Ord. 2282 NCS §3, 2007.)

The most stringent regulations or standards, federal, state, regional, or local, shall apply. (Ord. 2282 NCS §3, 2007.)

The limitations on wastewater strength and prohibitions in these regulations may be supplemented with more

stringent limitations if:

A. The city determines that the limitations may not be suYcient to protect the operation of community sewers

and the POTW.

B. The city determines that the limitations may not be suYcient to enable the POTW to comply with water

quality standards, or eZuent limitations speciWed in the POTW’s NPDES permit, or the POTW’s general water reuse

permit.

C. The discharge is of such a nature that it alone or in combination with other discharges reduces or threatens

to impair the POTW eZuent, reuse, discharge, or sludge disposal options.

D. In the city’s evaluation, the discharge, alone or in combination with any other discharge, poses a threat or

unreasonable risk to the POTW or personnel.

The city may also, through the use of the permit, make speciWc allocations of pollutants to industries. These

allocations or local limits shall be across-the-board local limits (or "uniform concentration limits"), local limits by

industrial contributory Xow and industry-speciWc local limits by mass proportion.

These allocation methods shall not allow any increased loading of any pollutant to the POTW nor shall they allow

higher limits than federal categorical standards. These allocations or local limits shall be evaluated and adjusted

from time to time to ensure that the loading of any pollutant to the POTW on a system-wide basis is suYciently

low to ensure that the POTW can comply with existing and future regulatory requirements.

(Ord. 2282 NCS §3, 2007.)

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Industrial users must comply with applicable categorical pretreatment standards, national prohibited discharge

standards, the city’s prohibitions, the city’s local limits, or BMPs, whichever are most stringent. The categorical

pretreatment standards found in 40 CFR Chapter 1, Subchapter N, Part 405 through 471 are hereby incorporated

into this section.

The city may authorize the industrial user subject to a categorical pretreatment standard to forego sampling of a

pollutant regulated by a categorical pretreatment standard if the industrial user has demonstrated through

sampling and other technical factors that the pollutant is neither present nor expected to be present in the

discharge, or is present only at background levels from intake water and without any increase in the pollutant due

to activities of the industrial user, subject to the conditions set forth in 40 CFR 403.12(e)(2). This authorization is

subject to the following conditions:

A. The city may authorize a waiver where a pollutant is determined to be present solely due to wastewater

discharged from the facility; provided, that the wastewater is not regulated by an applicable categorical

pretreatment standard and otherwise includes no process wastewater.

B. The monitoring waiver is valid only for the duration of the e[ective period of the permit, but in no case longer

than Wve years. The industrial user must submit a new request for the waiver before the waiver can be granted for

each subsequent permit.

C. In making a demonstration that a pollutant is not present, the industrial user must provide data from at least

one sampling of the facility’s process wastewater prior to any treatment present at the facility that is

representative of all wastewater from all processes. The request for a waiver must be signed by the authorized

representative of industrial user and include the certiWcation statement in 40 CFR 403.6(a)(2)(ii). Nondetectable

sample results may only be used as a demonstration that a pollutant is not present if the EPA approved method

from 40 CFR Part 136 with the lowest minimum detection level for that pollutant was used in the analysis.

D. A grant of the monitoring waiver by the city must be included as a condition in the industrial user’s permit.

The reasons supporting the waiver and any information submitted by the industrial user in its request for the

waiver must be maintained by the city for three years after expiration of the waiver.

E. Upon approval of the monitoring waiver and revision of the industrial user’s permit by the city, the industrial

user must certify on each report with the statement below, that there has been no increase in the pollutant in its

waste stream due to activities of the industrial user:

Based on my inquiry of the person or persons directly responsible for managing compliance with the

Pretreatment Standard for 40 CFR ______ [Specify applicable National Pretreatment Standard part(s)], I

 certify that, to the best of my knowledge and belief, there has been no increase in the level of _______ [list

pollutant(s)] in the wastewaters due to the activities at the facility since Wling of the last periodic report

under 40 CFR §403.12(e)(1).

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F. In the event that a waived pollutant is found to be present or is expected to be present based on changes that

occur in the industrial user’s operations, the industrial user must immediately: comply with the monitoring

requirements in 40 CFR 403.12(e)(1) or other more frequent monitoring requirements imposed by the city; and

notify the city.

G. This provision does not supersede certiWcation processes and requirements established in categorical

pretreatment standards, except as otherwise speciWed in the categorical pretreatment standard.

(Ord. 2402 NCS §2, 2011; Ord. 2282 NCS §3, 2007.)

A. Background. Industrial local pretreatment limits may be expressed through conditions in the user’s permit as

narrative statements (typically prohibitions) such as in Section 15.48.020, numerical values such as those listed in

Section 15.48.030, or a combination of both expressed as best management practices (BMPs) (40 CFR 403.5(c)(4)).

Historically, BMPs only applied to groups of low Xow discharges that had similar processes and discharged similar

types of wastewater (e.g., photo processors and dentist oYces). However, with the recent lowering of indirect

discharge limitations and improved analytical methods, the city will begin using BMPs in cases where it is not

practical or economically feasible for an industrial user to monitor for or attain speciWc numerical pretreatment

limits. This section gives the city the ability to shift from numerical end-of-pipe chemical controls on an industrial

user to BMPs and pollution prevention as an e[ective way for the city to achieve compliance with NPDES permit

limits. BMPs are enforceable under 40 CFR 403.5(d). In cases where the national pretreatment standard requires

compliance with a best management practice or pollution prevention alternative, the industrial user shall submit

documentation as required by the city or the applicable national pretreatment standards to determine compliance

with the national pretreatment standard as a component of the baseline monitoring report as required by 40 CFR

403.12(b)(5)(ii), and industrial users not subject to categorical pretreatment standards must submit documentation

regarding BMP or pollution prevention implementation required by the city to determine the compliance status of

the industrial user as required by 40 CFR 403.12(h).

B. BMP use examples:

 1.   There is insuYcient Xow from an industrial user or a category of industrial users to obtain a

 representative wastewater sample (e.g., dentist oYces, photo processors).

 2.  The proposed local limit is less than the detection limit and/or quantiWcation level (40 CFR Part 136) of

the most stringent analytical procedure.

 3.  The BMP is clearly the most economically feasible method for regulating the pollutant of concern.

C. BMP Removal from Permit. The city may consider a request to remove the BMP requirement from the indirect

discharge permit if the permittee can demonstrate that the discharge is reasonably expected to meet the numeric

local limit. In cases where the numeric local limit is calculated to be negative and where the industry’s eZuent

sampling results for pollutants with BMP requirements are below the quantiWcation level, the city may also

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consider a permit modiWcation request. Relaxation of the permit conditions does not allow the industry to return

to its previous methods of operation.

D. Inspections, monitoring, and numeric eZuent limits may still be required by the city to verify that the industry

remains in compliance. At a minimum, a certiWcation statement is required certifying that the industry is operating

under its approved BMP and no changes have been implemented.

E. BMPs may be used at the discretion of the city where appropriate to meet such pretreatment standards in a

practical and economical fashion.

 1.   Dental practices shall implement the following BMPs to reduce the amount of mercury entering the

wastewater system as recommended by the California Dental Association in 2010 within six months of the

adoption date of the ordinance codiWed in this section:

       a.  Do not rinse amalgam-containing traps, Wlters, or containers in the sink as required by CCR Title 22.

      b.  Do not place amalgam, elemental mercury, broken or unusable amalgam capsules, extracted teeth

     with amalgam, or amalgam-containing traps and Wlters with medical “red-bag” waste or regular solid

     waste.

        c.   Recycle, or manage as hazardous waste, amalgam, elemental mercury, broken or unusable

   amalgam capsules, and extracted teeth with amalgam-containing waste from traps and Wlters. Empty

     dental amalgam capsules containing no visible materials may be disposed of as a non-hazardous waste.

      d.   Collect and store dry dental amalgam waste in a designated, airtight container. Amalgam, which is

     designated for recycling, should be labeled “Scrap Dental Amalgam” with the name, address and phone

   number of your oYce and the date on which you Wrst started collecting material in the container.

       e.  Keep a log of your generation and disposal of scrap amalgam; inspectors may ask to see this to

      verify that your oYce is managing it correctly.

           f.   Separate excess contact dental amalgam from gauze that is retrieved during placement and place in

    an appropriate container. Use chair side traps to capture dental amalgam.

       g.  Change or clean chair side traps frequently. Flush the vacuum system before changing the chair side

      trap.

      h.  Change vacuum pump Wlters and screens at least monthly or as directed by the manufacturer.

             i.   Check the p-trap under your sink for the presence of any amalgam-containing waste.

             j.    Eliminate all use of bulk elemental mercury and use only pre-capsulated dental amalgam for

   amalgam restorations.

       k.   Limit the amount of amalgam triturated (ground to a Wne powder) to the closest amount necessary

      for the restoration.

     The Petaluma Municipal Code is current through Ordinance 2916 NCS, passed December 1, 2025.

Title 15 Water and Sewage | Petaluma Municipal Code Page 96 of 142

             l.    Train sta[ that handle or may handle mercury-containing material in its proper use and disposal.

   m.   Install an amalgam separator compliant with ISO 11143.

n. Do not use bleach to clean the discharge system as this may mobilize legacy mercury and amalgam

      in the system.

F. Industrial users subject to BMPs as a means of complying with standards of this part shall maintain

documentation to demonstrate compliance with all BMP standards for the term of the permit or Wve years,

whichever is longer.

(Ord. 2402 NCS §2, 2011; Ord. 2282 NCS §3, 2007.)

The disposal of sludges, spent chemicals and hazardous materials generated shall be done in accordance with all

applicable federal, state and local laws, regulations and ordinances including: Section 405 of the Clean Water Act

(CWA); Subtitles C and D of the Resource Conservation and Recovery Act (RCRA); and Title 22, Division 4, Chapter

30 of the California Administrative Code. A record of disposal shall be maintained and available for review by the

city. (Ord. 2282 NCS §3, 2007.)

Users shall make wastewater acceptable under the limitations established in these regulations before discharging

to a community sewer. Any pretreatment facilities required to pretreat wastewater to a level acceptable to the city

shall be provided and maintained at the user’s expense. When pretreatment or special facilities are required to

make the industrial wastes acceptable, the industrial user shall be required to furnish a compliance schedule and

plans, approved prior to construction, showing the schedule of activities, time frame and method of pretreatment

proposed to meet applicable pretreatment standards and requirements. The industrial user shall also submit all

notices and self-monitoring reports required by the city necessary to assess and assure compliance by the

industrial user with pretreatment standards and requirements. Pretreatment facilities or measures shall be

installed in conformity with the approved plans and other city codes or regulations. The approval of the

pretreatment method will in no way relieve the user from the responsibility of modifying the facility as necessary

to produce an eZuent acceptable to the city under the provisions of these regulations. Any subsequent changes in

the pretreatment facilities or method of operation shall be reported to and be accepted by the city.

The e[ectiveness of the pretreatment unit discharging to the community sewer will be monitored by the city at the

discharger’s expense. All records relating to compliance of the pretreatment unit with discharge standards shall be

made available to the EPA or approval authority.

In addition to pretreatment, or separately, the city may require the user to develop and adopt a waste

minimization or pollution prevention plan to reduce the quantity of waste discharged to the POTW. If determined

     The Petaluma Municipal Code is current through Ordinance 2916 NCS, passed December 1, 2025.

Title 15 Water and Sewage | Petaluma Municipal Code Page 97 of 142

necessary, the city may require the user to control slug discharges and provide a slug discharge control plan under

40 CFR 403.8(f)(1)(B)(6). If determined necessary, the city may require the user to control nuisances as deWned in

Section 15.44.020(A)(48). (Ord. 2282 NCS §3, 2007.)