Setting Priorities for Addressing Discharges from Separate Sanitary Sewers -1996 

(part of the Enforcement Management System) 
CHAPTER X. Setting Priorities for Addressing Discharges from ' 

Separate Sanitary Sewers 
THE ENFORCEMENT MANAGEMENT SYSTEM 


NATIONAL POLLUTANT DISCHARGE ELIMINATION SYSTEM 


(CLEAN WATER ACT) 


CHAPTER X: 	 Setting Priorities for Addressing Discharges 


from Separate Sanitary Sewers 


I 

U.S. ENVIRONMENTAL PROTECTION AGENCY 


' 	OFFICE OF REGULATORY ENFORCEMENT 

1996 
ENFORCEMENT MANAGEMENT SYSTEM - CHAPTER X 

Setting Priorities for Addressing Discharges from 

Separate Sanitary Sewers 

Discharges of raw or diluted sewage from separate sanitary 

sewers before treatment can cause significant public health and 

environmental problems. The exposure of the public to these 

discharges and the potential health and environmental impacts are 

the primary reasons 'PA is developing this additional guidance on 

these discharges. This document provides a method of setting 

priorities for regulatory response, and serves as a supplement to 

the Enforcement Management System guidance (EMS, revised February 

27, 1986). As such, this document addresses only those 

discharges which are in violation of the Clean Water Act. As a 

general rule, the discharges covered by this guidance constitute 

a subset of all discharges from separate sanitary sewer systems. 

Legal Status 

In the context of this document, a "discharge from a 

=+parate sanitary sewer system" (or "discharge")is defined as 

axy wastewater (including that combined with rainfall induced 

iEfiltration/inflow) which is discharged from a separate sanitary 

sewer that reaches waters of the United States prior to treatment 

a= a wastewater treatment plant. Some permits have specific 

requirements for these discharges, others have specific 

prohibitions under most circumstances, and still other permits 

are silent on the status of these discharges. 

The lezal status of any of these discharges is specifically 

related to the permit lansuase - - and the circumstances under which -

tke discharge occurs. Many permits authorize these discharges 

when there are no feasible alternatives, such as when there are 

circumstances beyond the control of the municipality (similar to 

tke concepts in the bypass regulation at 40 CFR Part 122.41 (rn)). 

Ccher permits allow these discharges when specific requirements 

are met, such as effluent limitations and monitoring/reporting. 

Most permits require that any non-compliance including 

overflows be reported at the end of each month with the discharge 

mcnitoring report (DMR) submittal. As a minimum, permits 

generally require that overflow summaries include the date, time, 

duration, location, estimated volume, cause, as well as any 

cbserved environmental impacts, and what actions were taken or 

are being taken to address the overflow. Most permits also 

require that any non-compliance including overflows which may 

endanger health or the .en$gcn@nt be :reported w$gi$;2! hours, 

and in writing within five :days..- ~xam~lesof overflows .whichmay 

ezdanger health or the .en~v_i~&~e,nt .i-ncl.ude..,ma jor,;.;ne'.,breaks, 

c~icrflow events which 'result:;:in'fish-killsor other-,significant 

?.~rx, and overflow events which occur'in environmentally 

s3xitive areas. 
For a person to be in violation of the Clean Water Act: 


1) a person must own, operate, or have substantial control over 


the conveyance from which the discharge of pollutants occurs, 


2) the discharge must be prohibited by a permit, be a violation 


of the permit language, or not be authorized by a permit, and 3)
 the discharge must reach waters of the United States. In 


addition, discharges that do not reach waters of the United 


States may nevertheless be in violation of Clean Water Act permit 


requirements, such as those requiring proper operation and 


maintenance (O&M), or may be in violation of state law. 


Statement of Principles 


The following six principles should be considered as EPA 


Regions and States set priorities for addressing violating 


discharges from separate sanitary sewers: 


1. ~lldischarges (wet weather or dry weather) which cause or 

czntribute significantly to water quality or public health 

~r~blerns(such as a discharge to a public drinking water supply) 

skould be addressed as soon as physically and financially 

~cssible. Other discharges may, if appropriate, be addressed in 

th2 context of watershed/basin plans (in conjunction with state 

or federal NPDES authorities) . 

2. Discharges which occur in high public use or public access 


areas and thus expose the public to discharges of raw sewage 


(i.s., discharges which occur in residential or business areas, 


near or within parks or recreation areas, etc.) should be 


addressed as soon as physically and financially possible. 


3. Dry weather discharges should be addressed as soon as 


~~ysically
 and financially possible. 


t. Discharges due to inadequate operation and routine 

ezintenance should be addressed as soon as possible. (Physical 

azd financial considerations should be taken into account only id 

cases where overflow remedies are capital intensive.) 

5. Discharges which could be addressed through a comprehensive 

creventive maintenance program or with minor capital investment 

should be addressed as soon as physically and financially 

possible. 

6. With respect,to principles 1 through 5 above, schedules of 


compliance which require significant capital investments should 


take into account the financial capabilities of the specific 


municipality, as well as any procedures required by state and 


lccal law for publicly owned facilities in planning, design, bid, 


award, and construction. (See later sections on Schedules). 

Causes of Sanitary Sewer Discharges 


Discharges from separate sanitary sewers can be caused by a 


variety of factors including, but not limited to: 


1. Inadequate O&M of the collection system. For example; 


failure to routinely clean out pipes, failure to properly seal or 


maintain manholes, failure to have regular maintenance of 


deteriorating sewer lines, failure to remedy poor construction, 


failure to design and implement a long term replacement or 


rehabilitation program for an aging system, 'failure to deal 


expeditiously with line blockages, or failure to maintain pump 


=Lacions (including back-up power). 


2. Inadequate capacity of the sewer system so that systems 

which experience increases in flow during storm events are unable 

to convey the sewage to the wastewater treatment plant. For 

example, allowing new development without modeling to determine 

=he impact on downstream pipe capacity, insufficient allowance 

fzr extraneous flows in initial pipe design (e.g. unapproved 

cz-nection of area drains, roof leaders, foundation drains), or 

ov5rly optimistic Infiltration/Inflow reduction calculations. , 

3. Insufficient capacity at the wastewater treatment plant so 


that discharges from the collection system musr occur on a 


rqular basis to limit flows to the treatment plant. For 


example, basic plant designs which do not allow sufficient design 


ca~acitv for storm flows. 


a4. Vandalism and/or facility or pipeline failures which occur 

i-dependent of adequate O&M practices. ' ,

Applicable Guidance 


. - For many years, EPA and the States have been working with -.,,.,.,icipalitiesto prevent discharges from separate sanitary sewer 

s:;scerns. The preferred method has been to use the general policy 

c- responding to all violations of the Clean Water Act which is 

c-r-.rained in the EMS guidance. Factors which are considered are 

tk2 frequency, magnitude, and duration of the violations, the 

environmental/public health impacts, and the culpability of the 

viclator. This guidance sets up a series of guiding principles 

for responding to separate sanitary sewer discharge violations, 

a.:d it supplements the current EMS. 

Every EPA Region and State uses some form of this general 

scforcement response guidance as appropriate to the individual 

scate processes and authorities. Under the guidance, various EPA 

Sqions and States have taken-a ' -.- large number of-Formal ry- O-r --.-..-a -.*-c. ,.. ..--. tzfcrcement actions over th~ipast several years to address 

saritary sewer discharge problems across the country. Res?cnses 

:.,,=---.-included administrative orders and/or civil judicial actic~s 
against larger municipalities to address sanitary sewer discharge 


problems, resulting in substantial injunctive relief in some 


cases. 


As a result of EPA Region and State enforcement efforts, a 

number of municipalities have invested substantial resources in 

diagnostic evaluations and designing, staffing, and implementing 

O&M plans. Other municipalities have undertaken major 

rehabilitation efforts and/or new construction to prevent . 

sanitary sewer discharges. 

Priorities for Response 


There are approximately 18,500 municipal separate sanitary 

sewage collection Systems (serving a population of 135 million), 

all of which can, under certain circumstances, experience 

discharges. Given this fact, the Agency has developed a list of 

priorities in dealing with the broad spectrum of ssparate 

sa3itary sewer discharges to ensure that the finite enforcement 

rssources cf EPA and the States are used in ways that result in 

caximum ecvironmental and public health benefit. However, these 

priorities should be altered in a specific situation by the 

de~ree of health or environmental risks presented by the 

condition(s). 

In the absence of site-specific information, all separate 


sanitary sewer discharges should be considered high risk because 


such discharges of raw sewage may present a serious public health 


and/or environmental threat. Accordingly, first priority should 


be given within categories (such as dry weather discharges and 
 ,.V.=- .- t weather discharges) to those discharges which can be. most 

quickly addressed. The priority scheme listed below takes this 


into account by first ensuring that municipalities are taking all 


ctcessary s~eps to properly operate and maintain their sewerage 


=.,-sterns. Corrective action for basic O&M is typically 


azcomplished in a short time, and can yield significant public 


kralth and environmental results. 


Risk again becomes a determinant factor when conditions 


warrant long term corrective action. The goal here should be to 


e.-.sure that capital intensive, lengthy compliance projects are 


7xioritized to derive maximum health and environmental gains. 


The priorities for correcting separate sanitary sewer 


discharges are typically as follows: 


1) Dry weather, O&M related: examples include lift stations or 


pumps that are not coordinated, a treatment plant 


that is not adjusted according to the influent-.flow, poor 


csrnmunication between field crews and management, 


ir.filtration/inflow, and/or pretreatment problems. 

2) 'Dry weather, preventive maintenance related: examples include 


pumps that fail due to poor maintenance, improperly calibrated 


flow meters and remote monitoring equipment, insufficient 


maintenance staff, deteriorated pipes, and/or sewers that are not 


cleaned regularly. 


3) Dry weather, capacity related: examples include an 


insufficient number or undersized pumps or lift stations, 


undersized piges, and/or insufficient plant capacity. 


4) Wet weather, O&M related: examples include excessive inflow 


and/or infiltration (such as from improperly sealed manhole 


covers), inadequate pretreatment program (i.e. excessive 


industrial connections without regard to line capacity), 


uncoordinated pump operations, treatment plant operation tha: is 


not adjusted according to the influent flow, poor coordination 


between field crews and management, illegal connections, and/or 


no coordination between weather forecast authorities and sewer 


system masagement. 


z \ Wet weather, preventive maintenance related: examples 

include poor pump maintenance leading to failure, improperly 

calibrated flow meters and remote monitoring equipment, 

insufficient maintenance staff, and/or sewers that are not 

cleaned regularly. 

6) Wet weather, O&M minor capital improvement related: examples 

include the upgrading of monitoring equipment, pumps, or computer 

~r3grams, and/or repair or replacement of broken manholes or 

czlla~sed pipes. 

7 i Wet weather capacity, quick solution related: examples 

include a known collection system segment that is a "bottleneck", 

pumps beyond repair in need of replacement, and/or need for 

a.5ditional crews or technical staff. 

E) Wet weather, capacity, health impact related requiring long * 

term corrective action: examples include frequent discharges to 

~ublic recreational areas, shellfish beds, and/or poor 

re treatment where the total flow is large. 


51 Wet weather, capacity, sensitive area related requiring long 

term corrective action: examples include discharges to 

ecglogically and environmentally sensitive areas, as defined by 

State or Federal government. 

Selecting A Response 


The appropriate regulatory response and permittee response 


fcr separate sanitary sewer discharges will depend on the 


scecifics of each case. The regulatory response can be informal, 

-=--rial, --. or some combination thereof. Typical regulatory 
responses include a phone call, Letter of Violation (LOV), 


Section 308 ~nformation Request, ~dministrative Order (AO), 


Administrative Penalty Order (APO), and/or judicial action. The 


permittee response can range from providing any required 


information to low cost, non-capital or low capital improvements 


to more capital intensive discharge control plans. 


The attached chart lists some categories of separate 
 n

sanitary sewer noncompliance along with the range of response for 


eac'h instance. The chart is intended as a guide. The responses 


listed on the chart are not to be corisidered mandatory responses 


in any given situation. EPA and the States should use the full 


range of regulatory response options (informal, formal, or some 


combination thereof) to ensure that the appropriate response or 


remedy is undertaken by the permittee or municipality. All 


regulatory responses should be in accordance with the concept of 


the EMS regarding orderly escalation of enforcement action. 


Developing Compliance Schedules 


A compliance schedule should allow adequate time for all 

p?.ases of a sanitary sewer discharge control program, including 

csvelopmefit of an O&M plan, diagnostic evaluation of the 

c3llector system, construction, and enhanced O&M. 

Mxticipalities should be given a reasonable length of time to 

develop schedules so they can realistically assess their 

cerrpliance needs, examine their financing alternatives, and work 

ouc reasonable schedules for achieving compliance. Nevertheless, 

tirelines for schedules should be as short as physically and 

fizancially possible. 

Short Term Schedules 


In general, short term schedules would be appropriate for 


sanitary sewer discharges involving O&M problems, or where only 


zinor capital expenses are needed to correct the problem. The 


schedule should have interim dates and a final compliance date 


izcorporated in the administrative order or enforcement 


mechanism. 


Comprehensive Discharge Control Schedules 


Comprehensive discharge control schedules should be used 


where specific measures must be taken to correct the discharges, 

and the measures are complicated, costly, or require a 

significant period of time.-td' implement. If appropriate, these 

schedules should include the use of temporary measures to address 

hich impact problems, espe2i-a_lly wher$-. ..a -long term project is 

required to correct the sanitary sewer discharge violation. 

When working with municipalities to develop comprehensive 


sckedules, EPA Regions and St'ates should'be sensitive to their 

special problems and needs, including consideration of a 


municipality's financial picture. Factors that should be 


considered are the municipality's current bond rating, the amount 


cf outstanding indebtedness, population and income information, 


qrant eligibility and past grant experience, the presence or 


absence of user charges, and whether increased user charges would 


be an effective fund-raising mechanism, and a comparison of user 


charges with other municipalities of similar size and population. 


Physical capability should be considered when schedules are 

developed. Schedules sahould include interim milestones and 

iztermediate relief based on sound construction techniques and 

scheduling such as critical path method. Compliance schedules 

should be based on current sewer system physical inspection data 

adequate to design sanitary sewer discharge control facilities. 

Schedules should not normally require extraordinary measures such 

2s overtime, short bidding times, or other acceleraced building 

techniques. Where possible, schedule development should be 

cznpleted according to normal municipal government contrac:inc 

rssairements. 

Financial capability should also be considered in schedule 


d~v~loprnent,including fiscally sound municipal financing 


techniques such as issuing revenue bonds, staging bond issuance, 


seq~encing project starts, sensitivity to rate increase 


percentages over time. 


KC:~: The intent of this guidance is to aid the Regions and 


Zz2:2s in setting priorities for enforcement actions based on 


lizited resources and the need to provide a consistent level of 


response to violations. This does not represent final Agency 


ion, but is intended solely as guidance. This guidance is not 

~rcended for use in pleading, or at hearing or trial. It does 

r.2~create any rights, duties, obligations, or defenses, implied 

=r otherwise, in any third parties. This guidance supplements ' 

tk? Agency's Enforcement Management System Guide (revised -

.-Lruary 27, 1986) . 
ATTACHMENT 


CHAPTER X 

.. . . ENFORCEMENT RESPONSE GUIDE 

DISCHARGES FROM SEPARATE SAVITARY SEWERS 

Discharge without a 


permit or in viol?tion 


of generhl Sohibtion 


Discharge u ithout a perm~t 

- -or in violarlon of general , prohibition 

Discharge w~thout a permit 


or in violation of general 


prohibition 


Discharge without a permit 


or in violation of general 


prohibition 


Dlscn~rge u~thout a permit 


or In b iolut~on of general 


prohibition ' 


Discharge without a permit 


or in violation of general 


prohibition 


Discharge without a permit 


or in \ iolation of general 


prch~b~tion 


Dbch~rge ulthout a pemlt 


or In violation of general 


prohrbltlon 


D~scharge wlthout a permit 


or in violation of general 


prohibition 


Discharge without a permit 


or in violation of general 


prohibition 


Isolated & infrequent. 

dry weather O&hf 

related 

Isolated & infrequenr. 

dry weather capacity 

related 

Isolated & infrequent. 

wet weather O&M 

related 

i 

Isolated & infrequent. 

wet weather, quick and 

easy solution 

Isolated & infrequent, wet 

weather capacity related, 

he?lth and/or sensitive areas 

Isolated & infrequent, wet 

weather capaciry related, 

non-health, non-sensitive areas 

Cause unknown 

Permittee does not respond 

to letters, does not follow 

through on verbal or written 

agreement 

Frequent, does not significantly affect water quality, 

no potential public health 

impact 

Frequent, cause or contribute 

siznificantly to WQ problems, 

or occur in high public use and 

public access areas, or orherwise affect public health 

Phone call. LOV, 

308 request 

J 

308 req'uest. AO. 

APO. Judicial action 

Phone call, LOV. 

308 request 

LOV, 308 request 

LOV. 308 request, A0. 

APO 

Phone call, LOV, 308 

request 

Phone call, LOV, 308 


request 


AO, APO, judicial 


action 


LOV, 308 request. 

AO. APO 

AO, APO, judicial 

action 
ENFORCEMENT RESPONSE GUIDE 


DISCHARGES FROh.1 SEPARATE SSLNITARY SEWERS 


NONCOMPLIANCE RANGE OF RESPONSE 

Missed interim date in CDCP Will nor cause late final date LOV 

or other interim dates 

hlissed interim date in CDCP LVill result in other missed LOV. AO. .\PO. 

dates. no good and valid cause judicial action 

Missed final dare in CDCP Violation due to force Contact permitter and 

majeure require documenration of 

good or valid cause 

hlissed fins1 date in CDCP Failure or rehsal to comply AO. APO or judicial 

without good and valid action 

cause 

Failure to repon overflows Isolated and infrequent, Phone call, LOV, AO, APO 

(as sprciried in permit) health related 

Failure til repon overflows Isolated and infrequent, water Phone call, LOV.' AO, APO 

(as specified in permit) qualicy and environment related 

Failure to repon overflo~s Permittee does not respond to AO, APO, judicial action, 

(as specified in permit) letters, does not follow through request for criminal 

on verbal or written agreement. investigation 

or frequent violation 

Failure to repon permit Any insunce Phone. LOV. AO, APO 

rquirements 

CDCP=Comprehensive Discharge Control Plan