Fairfield-Suisun Sewer District

2003 NPDES Permit Renewal

Infeasibility Analyses

June 17, 2003

Introduction

These infeasibility analyses and resulting requests for compliance
schedule and interim limits are submitted to the Regional Water Quality
Control Board (RWQCB) by Fairfield-Suisun Sewer District to demonstrate
the District’s inability to comply with the proposed water-quality
based effluent limits for copper, mercury, cyanide, dichorobromomethane,
bis(2-ethylhexyl) phthalate, 4,4’-DDE, and dieldrin.  

Background

The Policy for Implementation of Toxics Standards for Inland Surface
Waters, Enclosed Bays and Estuaries of California (known as the State
Implementation Policy (SIP), March, 2000) establishes statewide policy
for NPDES permitting.  The SIP provides for the situation where an
existing NPDES discharger cannot immediately comply with an effluent
limitation derived from a California Toxics Rule (CTR) or Basin Plan
criterion.  The SIP allows for the adoption of interim effluent limits
and a schedule to come into compliance with the final limit in such
cases.  To qualify for interim limits and a compliance schedule, the SIP
requires that an existing discharger demonstrate that it is infeasible
to achieve immediate compliance with the CTR- or Basin Plan-based limit.


The term “infeasible” is defined in the SIP as “not capable of
being accomplished in a successful manner within a reasonable period of
time, taking into account economic, environmental, legal, social and
technological factors.” 

The SIP requires that the following information be submitted to the
Regional Board to support a finding of infeasibility:

documentation that diligent efforts have been made to quantify pollutant
levels in the discharge and sources of the pollutant in the waste
stream, including the results of those efforts;

documentation of source control and/or pollution minimization efforts
currently under way or completed;

a proposed schedule for additional or future source control measures,
pollutant minimization or waste treatment; and

a demonstration that the proposed schedule is as short as practicable.

Pollutants to be Evaluated 

The pollutants for which interim limits are needed for the District are
as follows:

copper 

mercury

cyanide

dichlorobromomethane

bis(2-ethylhexyl) phthalate

4,4’-DDE

Dieldrin

Effluent Limit Attainability

The proposed final and interim effluent limits contained in the draft
tentative order for copper, mercury, cyanide, dichlorobromomethane, bis
(2 ethylhexyl)phthalate, 4,4’-DDE, and dieldrin are compared to the
maximum observed effluent concentrations for these constituents in Table
1. 

Table 1.  Proposed Effluent Limits for Fairfield-Suisun Sewer District

Pollutant	Water Quality Based Effluent Limits	Performance-Based Interim
Effluent Limits 	Fairfield-Suisun 

Effluent Quality

	AMEL1	MDEL2	Daily Max.	Monthly Avg.	MEC3

Copper	4.7	7.5	12.3

10

Mercury	0.021	0.040

0.023	0.021

Cyanide	0.4	1.0	32

28

Dichlorobromomethane	46	88	75

55

Bis(2-ethylhexyl) phthalate	5.9	11.8	13

13

4,4’-DDE	0.00059	0.00118	0.05

<0.001

Dieldrin	0.00014	0.00028	0.01

<0.002

All values in µg/L.

1AMEL: average monthly effluent limit

2MDEL: maximum daily effluent limit

3MEC: maximum effluent concentration

The final effluent limits shown above are calculated using procedures
described in Section 1.4 of the SIP.  Background values are based on
Regional Monitoring Program (RMP) data collected at the Sacramento River
Station.  Dilution was taken as zero and the receiving water was
classified as estuarine (i.e., lowest of freshwater and saltwater
criteria is used for effluent limit calculation).  Hardness, where
applicable, was assumed to be 268 mg/L.  Other variables in the effluent
limit calculation included coefficients of variation for different
pollutants in different effluents.

Maximum observed effluent concentrations are based on recent plant
effluent quality data (2000-2002).  As shown in the table above, the
District will not be able to immediately comply with proposed effluent
limits for copper, mercury, cyanide, dichlorobromomethane,
Bis(2-ethylhexyl)phthalate, 4,4’-DDE, and dieldrin. The feasibility
analyses for these constituents are discussed below.

Source Control and Pollution Prevention Efforts 

In addition to its pretreatment program which regulates 11 industries
and 3 groundwater remediation sites, the District has an active
pollution prevention program that has been in place since 1992.
Currently, the District considers mercury, organophosphate pesticides,
perchloroethylene, copper, nickel, lead and zinc to be pollutants of
concern.  Mercury has the highest priority (A) while pesticides and
perchloroethylene are assigned a B priority and the metals are priority
C.  The District has implemented a variety of activities targeting these
pollutants over the years. Some of these activities are highlighted in
Table  2.

Table 2.  Fairfield-Suisun Pollution Prevention Program Activities

Pollutant of Concern	Source Control Activities

Mercury	Thermometer exchanges, Dental outreach

Organophosphate pesticides	Restaurant IPM inspections, school outreach,
theatre slides, public events, PCO workshops

Perchloroethylene	Dry cleaner inspections

Copper, nickel, lead, zinc	Inspections/ BMPs for vehicles service
facilities,  metal fabricators, and industry; surface cleaner workshops



Several of the activities listed above have been conducted in
cooperation with other local agencies in Vacaville, Vallejo, Fairfield
and Suisun City.  The District is also an active participant and
supporter of several regional groups and programs, including:

Bay Area Pollution Prevention Group (BAPPG)

Bay Area Clean Water Agencies (BACWA)

Bay Area Stormwater Management Agencies Association (BASMAA)

North Bay Source Control Group

Napa/ Solano Regional Environmental Public Education Group

Solano County Environmental Management Local Task Force

Napa/Solano Air Resource Team 

Additional information on pollution prevention activities targeting each
constituent requiring interim effluent limits is discussed below.

Copper

The maximum observed effluent concentration for copper is 10 µg/L
(measured in June 2000) which would exceed a final MDEL of 7.5.  The
maximum average monthly copper value of 8.5 (measured January 2001) 
exceeds the proposed final AMEL of 4.7.  In addition, 3 of 78 samples
taken between January 2000 and December 2002 have copper concentrations
that would exceed 7.5 (the proposed final MDEL) and 14 of 36 calculated
monthly average values would exceed 4.7 (the proposed final AMEL).  The
District will not be able to immediately comply with the proposed final
limits.

The District has identified copper as a priority C pollutant of concern
and has conducted pollution prevention targeting copper sources
including corrosion of copper plumbing, root control products, vehicle
service facilities, mobile surface cleaners, and metal fabricators. 
Pollution prevention activities have contributed to a 34% reduction in
copper influent levels between 1992 (59 µg/L) and 2000 (39 µg/L). The
District has conducted source control for most of the common copper
sources so it is not clear how much more reduction may be achieved.  The
District will review its current copper pollution prevention activities
and modify as needed.

Mercury 

The maximum observed effluent concentration for mercury is 0.021 µg/L
(measured in October 2002) which is equal to the proposed final AMEL of
0.021 µg/L.  The maximum average monthly mercury value of 0.015 µg/L
(measured in October 2002) does not exceed the final AMEL of 0.021. The
District will have difficulty consistently complying with the proposed
effluent limits.

Mercury is a 303(d)-listed parameter and is the subject of a TMDL
currently nearing completion. Final effluent limits for this pollutant
will be derived from the wasteload allocation established under the
TMDL.  The final effluent limit listed above for this pollutant is
projected to change based on the results of the TMDL and wasteload
allocation.  Available information indicates that mercury is a legacy
pollutant in San Francisco Bay resulting from past activities and that
ongoing loadings from POTWs are not a significant source of this
pollutant.  As a result, costly measures for either advanced treatment
or zero discharge to control mercury loading from POTWs are not expected
to be required.

Given that POTWs are not a significant source of mercury in the Bay, in
addition to the District’s existing high quality effluent, residential
service area, and favorable discharge location, it is not immediately
evident the extent to which additional pollution prevention efforts
would be effective or have any detectable beneficial impact on the
receiving water.  Certainly, the highest value measured by the District
is below the water quality objective.  Reasonable potential was only
triggered by background ambient data.

However, the District has a identified mercury as a pollutant of concern
and has conducted pollution prevention activities for mercury sources
including thermometer exchange programs in cooperation with other local
agencies, and outreach to dentists in the District’s service area.  In
addition, the District conducted a study of the impact of its effluent
on methyl mercury levels in Suisun Marsh. The District will continue its
efforts targeting mercury sources.  Specifically, the District has
surveyed local dentists regarding their amalgam waste management
practices and will develop future outreach based on the results of the
survey.

Cyanide

The maximum observed effluent concentration for cyanide is 28 µg/L
(measured in June 2001) which would exceed a final MDEL of 1.0 µg/L. 
The maximum average monthly cyanide value of 17 (measured June 2001) 
exceeds the proposed final AMEL of 0.4 µg/L..  In addition, 32 of 74
samples taken between January 2000 and December 2002 have cyanide
concentrations that would exceed 1.0 (the proposed final MDEL), one
sample has a cyanide concentration of 1 µg/L, and the remaining 41
samples have cyanide concentrations below the detection limit of 3
µg/L.  All the calculated monthly average values would exceed 0.4 µg/L
(the proposed final AMEL).  The District will not be able to immediately
comply with the proposed final limits and will have difficulty
consistently complying with the proposed interim limits.

Cyanide has been detected occasionally (i.e., 6 of 30 samples from
January 2000 – December 2002) but not consistently in the District’s
influent. Typically, cyanide is not present in wastewater influent but
is generated in the treatment plant disinfection process.  For example,
based on a review of the literature1 (including a study being conducted
by water Environment Research Foundation (WERF)), effluent cyanide
levels may be due to chlorination processes or may be the result of
analytical interferences.  

The District has not previously identified cyanide as a pollutant of
concern and, therefore, has not conducted source investigations for this
constituent.  In addition, as noted above, it is unlikely that these
investigations would be fruitful based on the influent data. A special
study is being conducted under a region-wide effort to develop a
site-specific objective for cyanide which is expected to more closely
represent actual water quality conditions than current water quality
objectives.  The District is participating in this study.  In addition,
in accordance with the requirements of its NPDES permit, the District
conducted a Cyanide Reduction Study focusing on determining if cyanide
was being generated in the treatment process.  The study determined that
it was likely that cyanide levels in the effluent were an artifact of
the chlorination/dechlorination process.   This study was submitted to
the Regional Board in February 2000.

Dichlorobromomethane

The maximum observed effluent concentration for dichlorobromomethane is
55 µg/L (measured in September 2002) which would exceed the proposed
final AMEL of 46 µg/L..  Of the 6 samples taken between January 2000
and December 2002, two have dichlorobromomethane concentrations that
would exceed 46 µg/L (the proposed final AMEL).  The District will not
be able to immediately comply with the proposed final limits.

Dichlorobromomethane is generated as a byproduct of chlorination of
water and wastewater and does not typically have influent sources.  The
District has not previously identified dichlorobromomethane as a
pollutant of concern and, therefore, has not conducted pollution
prevention activities for this constituent.  Influent levels of
dichlorobromomethane average less than 1 µg/L  and have not exceeded
2.1 µg/L.  Therefore, it is unlikely that there are significant sources
of dichlorobromomethane in the influent, making source investigations
and source control activities unlikely to be fruitful.  With only six
influent and effluent samples in 3 years, there is not enough
information to completely assess the District’s ability to comply with
the proposed interim or final limits.  Should reductions be necessary,
the District will evaluate its treatment plant processes to determine if
there are opportunities to optimize its processes to reduce generation
of dichlorobromomethane. 

Bis(2-Ethylhexyl)Phthalate 

The maximum observed effluent concentration for
bis(2-ethylhexyl)phthalate is 13 µg/L which exceeds the proposed final
MDEL of 11.8 µg/L and the proposed final AMEL of 5.9 µg/L..  Only 7
data points are available for January 2000 through December 2002 with
the two earliest samples having high detection limits (i.e., 25 µg/L). 
The District will have difficulty complying with the proposed interim
and final limits but insufficient data are available to assess
compliance with any certainty.

Bis(2-ethylhexyl)phthalate (Bis-2) is a plasticizer.  Approximately 97%
of the Bis-2 produced annually is used as a plasticizer for PVC and
other plastics.  Because of the widespread use of plastics in every
facet of everyday life, Bis-2 is ubiquitous. Influent levels of Bis-2
average 30 µg/L.  The District has not previously identified Bis-2 as a
pollutant of concern and, therefore, has not conducted pollution
prevention activities for this constituent. With only seven effluent
samples in 3 years and six influent samples, there is not enough
information to completely assess the District’s ability to comply with
the proposed interim or final limits.  Since high levels of Bis-2 in
POTW effluent are usually associated with sampling and/or laboratory
analysis conditions, the District proposes to conduct a special study to
determine if cleaner sampling and analysis techniques can reduce the
amount of Bis-2 in the effluent.  

4,4’-DDE, Dieldrin

The chlorinated pesticides, 4,4’-DDE and dieldrin , have not been
detected in the District’s effluent and have been below reporting
limits of 0.01 µg/L. The reporting limits and the detection limits
(0.001 µg/L for 4,4’-DDE and 0.002 µg/L for dieldrin) exceed the
proposed final limits for both constituents.  Therefore, there is
insufficient information to determine if the District is able to comply
with the proposed effluent limits.

4,4’-DDE is a decomposition product of DDT, which was banned in the US
for most uses in 1972 and all remaining uses in 1988.  Dieldrin was
banned for most uses in 1974 and all remaining uses in 1987.  Dieldrin
is also a decomposition product of Aldrin whose use was also
discontinued in the late 1980’s.  The District has not previously
identified 4,4’-DDE or dieldrin as pollutants of concern and,
therefore, has not conducted pollution prevention activities that
directly target these constituents.  However, the District has an
ongoing pesticide pollution prevention program that includes a
restaurant Integrated Pest Management (IPM) education program,
residential outreach (theatre slides, bus boards, public events), school
outreach and PCO workshops.  As noted above, there is insufficient
information to completely assess the District’s ability to comply with
the proposed effluent limits for 4,4’-DDE and dieldrin.  Since
reasonable potential for these constituents is triggered only by
background ambient conditions, the District will continue existing
efforts for pesticides generally.

Summary

This evaluation indicates that immediate compliance with projected final
effluent limits for copper, mercury, cyanide, bromodichloromethane,
bis(2-ethylhexyl) phthalate, 4,4’-DDE and dieldrin is not feasible for
the District.

In accordance with the requirements of the SIP, the District requests
that the Regional Board refrain from the adoption of final effluent
limits for these constituents.  In lieu of final limits, the NPDES
permit should include the interim performance based limits with which
the District can comply.  Proposed source control actions are shown in
Table 3 below.

Table 3.  Proposed Source Control Actions

Constituent	Proposed Action	Estimated Time to Complete

Copper	Existing outreach to municipal water supply agencies, plumbers,
vehicle service facilities, metal fabricators, and surface cleaners
Ongoing

Mercury	No additional activity since RP triggered by background data	N/A

Cyanide	Participate in study to develop site-specific objective	June,
2003

Dichlorobomomethane	Conduct source identification across plant processes
Three years after permit adoption

Bis(2-Ethylhexyl)Phthalate	Conduct study to evaluate clean sampling
Three years after permit adoption

4,4’-DDE	No additional activity since RP triggered by background data
N/A

Dieldrin	No additional activity since RP triggered by background data
N/A



 

 

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