C Inflow/Infiltration Report
CITY OF
CHANHASSEN
7700 Market Bou levard
PO Box 147
Charlhassen, MN 55317
Administration
Phone: 952,2271100
Fax, 9522271110
Building Inspections
Phone: 952,2271180
Fax, 9522271190
Engineering
Phone, 9522271160
Fax: 9522271170
Finance
Phone 9522271140
Fax: 9522271110
Park & Recreation
Phone: 952,2271120
Fax 9522271110
Recreation Center
2310 Cou Iter Bou levarcJ
PhOllC 9522271400
Fax 9522271404
Planning &
Natural Resources
Pholle 9522271130
Fax, 9522271110
Public Works
1591 Park Road
Phorle 952,2271300
Fax 952,2271310
Senior Center
Phone 9522271125
Fax 952,2271110
Web Site
www.cl.chanhasselì.illr1.us
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MEMORANDUM
TO:
:> <.
Paul Oehme, Public Works Director/City Engineer
Todd Gerhardt, City Manager
FROM:
Kelley Janes, Utility Superintendent
DA TE:
September 22, 2004
SUBJECT:
Sewer Flow Monitoring Program Status Update
The Inflow and Infiltration identification and Abatement Program, referred to as
the "I & I Program", was initiated and implemented to determine if costs in the
sanitary sewer fund could be reduced. As part of the I & I Program, sewer
outflows were identified and temporary and permanent monitoring of sites were
started. Six sites were monitored with temporary flow metering and one
permanent magnetic meter was installed at Lift Station No.4. The six temporary
sites were monitored each for one week on a rotational basis in an attempt to
gather flow profiles. The MCES (Metropolitan Council Environmental Services)
currently monitors five of the sites one week per year in each quarter on a
rotational basis. One of the sites is not monitored by MCES but per household
estimates are used for the site. Also, the MCES's method for monitoring Lift
Station No. 4's flow uses the City's hourly run-time readings for the lift station
pumps, multiplied by the designed gallon-per-minute output of the pumps. Flow
readings from our permanent meter at Lift Station No.4 shows slightly lower
readings when compared to the pump hourly reading calculations. Based on
staff's calculations approximately $900/year in savings have been identified at
this site. Staff will recommend MCES use our permanent meter at Lift Station
No.4 for billing. The other temporary sites monitored showed inconclusive data
comparison at this time. The flow measurements used by MCES is complicated,
incorporating a week of flow data, households connected to the drainage
outflows, and deduction calculations for neighboring community households
connected to the lines before their metering sites. Runtimes from lift stations in
border communities are also used in flow calculations.
To insure that a monitoring program is cost effective and expenditures can be
recouped in a reasonable amount of time, we would have to be able to prove that a
permanent monitoring program could show significant savings and that there is a
substantial disparity between our readings and those of MCES. At this time, staff
cannot prove this disparity exists. Permanent monitoring of the six sites would
cost approximately $48,000 for the equipment, and would require approximately
8 hours of staff time per month. Staff intends to keep working with MCES and
monitor flows on a temporary basis at each of the sites to better determine flow
profiles on a yearly basis.
The City of Chanhassen ·,A growlrlg ~OrTlmlJrllty with clearl lakes, quailty
Paul Oehme
Todd Gerhardt
September 22, 2004
Page 2
The MCES has recently implemented a program to reduce I & I in the seven
county metro area, due to a forecast of major capacity problems in the future.
Part of that program included informing individual cities of I & I events that
exceeded a set parameter. The attached executive summary of the I & I task force
report identifies the impact that excessive I & I can have on communities with
significant I & I problems. The full report does not identify Chanhassen as a
current high I & I contributor but this could change if the City's sewer system is
not maintained. On three occasions during this summer, the City exceeded this
threshold. In the near future, these exceedances may result in direct surcharges.
The monitoring the City has completed shows the cause to be primarily inflow.
Outside of the future surcharges, this is substantial flow that can't be billed to
resident users, as our sewer rates are set by winter water usage rates. I & I can
also cause sewer overflows and system backups, directly affecting resident's
personal property. The added flows also result in higher electrical usage and
premature wear on lift station pumps.
We have shown success in our abatement of I & I in the Lotus Lake area and
continue to pursue it in the areas near Lake Minnewashta. With the funding that
has been appropriated in the CIP, staff recommends to continue to identify and
eliminate as much of the I & I as possible in the system.
Attachment
G:\ENG\paul\mcmos\hg ws 92704 1&1 update. do\,;
Metropolitan Council Environmental Services
INFLow/lNFIL TRATION
TASK FORCE REPORT
EXECUTIVE SUMMARY
May 2004
~f' Metropolitan Council
~~ Environmental Services
230 East Fifth Street - St. Paul, Minnesota 55101-1626 - (651) 602-1005 - Fax 602-1138 - TTY 291-0904
Metropolitan Council Members
Roger Scherer
Tony Pistilli
Mary H. Smith
Julius C. (Jules) Smith
Russ Susag
Peggy Leppik
Annette Meeks
Lynette Wittsack
Chair:
Peter Bell
Council Members:
District 1
District 2
District 3
District 4
District 5
District 6
District 7
District 8
Natalie Steffen
Vacant
Georgeanne Hilker
Chris Georgacas
Richard Aguilar
Song Lo Fawcett
Thomas Egan
Brian McDaniel
District 9
District 10
District 11
District 12
District 13
District 14
District 15
District 16
General Manager, Environmental Services Division
William G. Moore
Council Regional Administrator
Thomas Weaver
The tnission of the Metropolitan Council is to develop~ in cooperation with local cOlntnunities~ a
conlprehensive regional planning franle\Vork~ focusing on transportation~ vvaste\vater~ parks and
aviation systenlS~ that guides the efficient gro\vth of the Inetropal itan area. The Counci I operates
transit and \vaste\vater services and adnlinisters housing and other grant progralns.
Publication #32-04-01 9
Released May 2004
Table of Contents
Introduction.................................................................................................................. .....1
Metropolitan Disposal System................................................................................................1
Interceptor Master Plan Findings...........................................................................................2
Task Force Creation...............................................................................................................2
Statement of the Problem............................................................................................. 3
Characterization of 1/1.............................................................................................................3
Impact of 1/1 on MCES Facilities .............................................................................................4
Impact of 1/1 on Local Sewer Systems....................................................................................4
Regulatory Environment.........................................................................................................5
Regional Cost Estimates........................................................................................................6
Alternatives Considered................................................................................................ 7
Regional versus Local Solutions............................................................................................ 7
Means of Enforcement...........................................................................................................7
Other Options....................................................................................................................... ..7
Financial Incentives. ...............................................................................................................8
Authority, Conclusions and Recommended Actions............................................9
Authority..................................................................................................................... ............9
Conclusions................................................................................................................... .......10
Recommended Actions........................................................................................................1 0
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Introduction
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Metropolitan Disposal System (MDS)
Metropolitan ("ouncil Environlnental Services (MCES) o\vns and operates extensive
interceptor systen1s'l as sho\vn in Figure I. l~he largest systenl conveys \vaste\\'ater tlo\v to the
Metro Waste\vater Treatnlent Plant and serves Figure 1: MCES Plants and Interceptor System
65 cOlnln un ities. Slnaller systelns convey
flow to the Counci)" s plants in Shakopee
(Blue Lake)' Eagan (Seneca)' Elnpire and
Stillwater (S1. Croix). There is no interceptor
systeln for the Hastings and Rosemount
plants and the interceptor systeln to the ne\v
Eagles Point Plant is under construction.
More than 100 cOlnnlunities own and operate
local sewer systelns that are connected to the
MCES regional interceptor systeln. rrhrough
these local systelns'l \vaste\vater serv ice is
extended to residents'l cOlnlnercial
establ ishlnents'l industry'l and pub I ic agenc ies.
These end users are charged for this service
by the local comln un ity.. \vh ich typically
charges for \\t'aste\vater on the basis of Inetered water use. MC ES'I as a \vholesaler of the
regional services.. bills each cOlnlnunity on the basis of its nletered \vaste\vater flo\v into the
interceptor systenl. Only industries \vith high strength \vaste are billed individually' by
MCES.
Anoka
C a rver
Dakota
Each com In unity bills its custolners to recapture the cost charged by MCES and the costs to
Inaintain and operate the local sewers. Because MC"ES bases its charge for service on the
volulne of wastewater received.. these charges reflect clear \vater entering the se\ver s)'stenl as
well as the wastewater generated by the custolners. rrhis includes rain induced clear \vater
that enters the local sew'er systcln through leaks in the publicly o\\/ned se\ver and Inanholes
and the private property sources: rain leaders. sUlnp pUlnps.. foundation drains'l and leaking
house laterals. MCES flo\v records sho\v a direct correlation bet\veen precipitation and the
volulne of clear water tlo\v froln ITIany cOITIlnunities served by the regional \vaste\,vater
systeln.
The addition of clear water into the local se\ver systenls creates t\VO problelns. First the
additional flow takes capacity that \vas originally designed for gro\vth and'l in SOITIe cases.. the
additional flo\v exceeds the available se\ver systeln capacity. When the capacity of the se\\er
is exceeded'l the \\'aste\vater backs up into baselnents or spills out of a Inanhole. These
occurrences are not allowable under federal and state regulations. Second'l MCES charges
cOlnrTIunities the same rate for its clear \vater as it does for the se\vage. COITIrTIunities..
therefore have a fiscal as well as a public policy reason tor assuring that the total systenl
functions effectively and confonTIs to federal and state regulations.
Interceptor Master Plan Findings
A cOlnprehensive Inaster plan for these interceptor systelns \vas cOlnpleted in Decell1ber
2002. One of the more significant findings of the study \vas that uncontalninated ground\\/ater
and rainfall runoff\vere entering the local collection systenls at rates that could overload the
interceptor systeln. Th is uncontall1 inated clear \vater.. called In fi Itrationll nflo\v (1/1)'1 is
consulning interceptor and treatlnent plant capacity originally designed to serve future
developlnent. During significant rainfall events'l portions orthe interceptor systenl are at risk
of causing a backup of \vaste\vater into a baselnent or spi II ing w'aste\vater into the
environlnent. Under state and federal regulations'l any spi II or backup is not allo\\able and is
subject to fines.
When a sewer systenl is overloaded'l the sewer bccolnes pressurized and \vaste\vater can tlovv
back up a house lateral into a basenlcnt. Even though the overloading nlay last only' an hour
or t\vo,\ enough till1e has passed to cause dalnage and create a health hazard in the lo\v-Iying
basements that essentially relieve the overloaded systenl. On occasion'l the systenl beCOIl1eS
so pressurized'l the \vaste\vater rises up in Inanholes and tlO\VS out the top of the nlanholc.
The overflow of untreated \vastc\vater into the environlnent can cause a health hazard and'l in
sOlne cases'l adversely affect the aquatic environlnent.
Task Force Creation
On April 8'12003'1 the Metropolitan ('ouncil appointed individuals to serve on the Infiltration
and Intlo\v Task Force,\ \vhich \vas chaired by a ('ouncil Melnber. The task force included
representatives frofn 15 communities frolll across the region as \v'ell as a representative froll1
the Association of Metropolitan Municipalities.
The task force was charged \vith revie\ving the 1/1 issues and f()nnulating and proposing
inlplelnentation strategies to reduce excessive Infiltration and Intlo\v (1/1) in local and
regional \vastewater collection systelns. Reporting back to the Environlnent COlnlnittee'l the
task force Inet Inonthly and reviewed infonnation presented by' Environlnental Services
Division staft: \vho provided facilitation and adlninistrative support. The recolnll1cndations
and conclusions \vere arrived at by consensus orthe task force Inelnbers.
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Statement of the Problem
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Sewers'l pUl11p stations and treatlnent plants are designed to convey and treat w'astc\vater.The
capacity or size of the facilities is dependent on the flo\v rate of the \vaste\vater. For
conveyance fàcilities'l the tlo\v rate is usually the InaXilnUl11 rate expected for a one-hour
duration. For treatlnent plants'l the structures Inust pass not only the 111axil11Ul11 rate 'I but the
processes are designed to Ineet penn it lil11its'l usually specitied as a peak 1110nth condition.
Consequently'l the Inaximuln 30 day average flo\v is ilnportant for sizing treatlnent plants.
l"'he introduction of non-contalninated'l clear \vater (1/1) into the collection systeln increases
the flow of the \vastewater and consulnes capacity of se\v'ers'l pun1p stations and treatl11ent
plants. Whenever the rate of 1/1 exceeds the initial basis of the design (solne allo\vance of 1/1
is included in the design)., the capacity allocated for gro\vth is no longer available. Therefore'l
larger facilities need to be constructed'l gro\vth needs to be curtailed.. or 1/1 reduced to
acceptable design levels.
The se\Vrer systeln that conveys \vaste\vater to the treatlllent plants can be characterized as the
publicly owned systeln.. typically located in public right-of-\vay (under streets or backyard
easelnents)., and the private systelll'1
typically the house lateral that extends
from the building to the publicly owned
sewer. As depicted in Figure 2'1 there
are several \vays for 1/1 to enter the
collection systeln.
Characterization of III
Figure 2: Sources of Infiltration/Inflow
Foundation drain or
sump pump connected
to house lateral
Yard drain connected to house lateral
I nfi Itration occurs when ground\vater
enters the san itary sewer systelll
through defects in the systenl. Inflow
occurs when stonll\vater/rain\vater
enters the sanitary se\ver systeln
through defects and illegal connections
in the systelll. Both infiltration and
inflow are characterized as clear \vater
that does not require treatlllent prior to
discharge.
Sources of intiltration are typically cracks in pipes.. leaky joints and deteriorated Inanholes.
Groundwater can enter these defects whenever the collection systelll I ies beneath the
ground\vater table or the soil above the se\ver nears saturation. rrypically'l the rain in1ìltrating
through the ground can cause an increase in \vaste\vater flo\\" if there are defects in the se\ver.
Sources of intlo\v are typically direct connections to the sanitary se\ver systen1: cross
connections with the stonn sewer systeln'l building rain leaders'l building foundation drains
and sUlnp pumps. These connections occur with both hOlnes and businesses. Intlo\v typically
occurs in direct proportion to rainfàll. Soon atter the rain stops.. the intlo\v fì·ol11 1110st sources
also stops. The exception is the response of a foundation drain or sunlp pUlnp that can
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continue for extended periods oftil11e as the \vater percolates through the overlying soil.
These sources cOlne fì·onl private property. Since the late 1960s the law has not allo\ved
connections of sunlp punlps,\ foundation drains and rain leaders froln houses to the local
sanitary' systeln. Howevec rnany hOlneo\vners are still connected via these sources to the
sanitary sew'er systel11. ('ornl11unities have found that reducing III fronl private property'
sources is politically difficult even though it is not legal for these sources to exist.
Impact of III on MCES Facilities
The Metropolitan ("ouncil has projected significant gro\vth in the Inetropolitan area by 2030.
These population and elnploYlnent projections \vere used to predict waste\vater flo\\/s
throughout the interceptor systel11 and at each treatlnent plant. For the interceptor systel11.
peak hour flows were projected: and for the treatl11ent plants'\ annual average'\ peak month'\
and peak hour tlO\VS w'ere projected. l'he infi Itration/inflo\v conlponent of peak hour flo\\'
rates w'as estinlated based on a cOlnputer Inodel silnulation of ho\v raintàll generates
infiltration/inflo\v in areas tributary to the interceptor SYStCI11.
Results of sil11ulating the projected conditions in 2030 using current levels of III indicate the
need for a significant investl11ent in relief se\vers and pUI11p stations. As sho\vn in Exhibits
E5-1,\ ES-2,\ ES-3'\ ES-4'\ and ES-5 at the end of this docul11ent segnlents of the interceptor
systeln would require extensive parallel se\vcrs and nlany pUlnping stations \\/ould require
expansion.
Peak hour flo\vs to each plant in 2030 \vere projected \vith the interceptor Inodel using 25-
year and 1 OO-year stonn events. The peak flo\v to the Metro plant could reach over 1.3
bi II ion gallons per day if enough rei ief se\vers were constructed. l~h is is nearly twice the rate
that the twin barrel joint interceptor can carry into the plant today. ~rhe feasibility ofdoubling
the hydraulic capacity of the Metro plant is not possible because of site constraints. MCES
staff has concluded that silnply adding l110re capacity to convey and treat III is not a feasible
option.
Impact of III on Local Sewer Systems
III is currently causing backup problelns in several cOlnl11unities,\ independent of the
interceptor systeln capacity. In these conll11unities the peak III is so signifìcant'\ the local
collection systeln is overloaded and ra\v se\vage is backing up into low-lying basenlents.
Where the local collection systenl is overloaded by IlL the Minnesota Pollution Control
Agency (MPC A) can prohibit additional connections to the local se\vers. This overload
condition essentially stops gro\vth or redevelopl11ent that increases \vaste\vater flo\v.
In a fe\v comlnunities served by an MC"ES pUlnp station'\ the peak flows during a significant
rain exceed the firnl capacity of the MCES punlp station. rrhese problelns are severe and
frequent enough for the Council to advise these cOlnlnunities that either 1/IInust be reduced
or local se\ver connections Inust be halted.
Excessive III rates can put the regional conveyance systenl at risk of being overloaded'\
consuming capacity that should be available for do\vnstrealn cOlnrnunities. In sor11e cases. the
excessive III frorn one conlnlunity can cause an overflo\v to occur in an adjacent conllnunity
in either direction. 1"0 reduce the risk of this occurrence. MCES (as the regional \\t'aste\vater
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agency) Inust advise the non-colllpliant cOlnnlunity of its liability and \vork \vith the
cOlnmun ity to reduce the excessive 1/1.
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Regulatory Environment
On January 5.. 200].. the United States Environlnental Protection Agency (U.S. EPA) signed
the long-aw'aited draft rule on sanitary se\ver overtlo\vs. As \vith other regulations.. the] 20-
day publ ic cOlnlnent period \vi II not begin unti I the proposed rule is publ ished in the Federal
Register. That publication \vas delayed on January 24 v.¡hen EPS \vithdre\v the SSG
regulations frolll the ()fticc of the Federal Register to give the Bush Adlllinistration an
opportunity to review the draft. Since January 200].. EPA has received hundreds of
conllnents to the original draft.. resulting in a directive to the ()ftice of Water Managelncnt to
do the following:
]. Propose regulations consistent \\'ith those originally reCOll1111ended.
2. Sumlnarize all COllllllents received since and incorporate theln into the preal11ble to the
regulations.
3. Provide prealnble discussion regarding the COlnnlcnts.
Publication in the Federal Register is still delayed. 'fhe dratt rule has been relnoved 1'1'0111 the
U.S. EP A Web site as of March].. 2004 and its status relnains uncertain. Mean\vhile.. as
Inunicipalities a\vait fonnal regulations.. the tàct relnains that roughly 22..000 cities in the
U.S. experience SSG during \vet w'eather conditions. [)espite the lack of fonnal SSe)
regulations.. these unpennitted/untreated discharges are still prohibited under the ('lean Water
Act and subject to enforcenlent action. l'his is a serious concern in areas \vhere \vastc\v'ater
tlow increases signiticantly because ofraint~lll. Even intì4equent rain events \v'ill not be a
valid excuse for an SSO.
At th is tiJne.. MC ES is the on Iy National Pollution I)ischarge E I illl ination Sy'steln (N PC) ES)
permit holder tor the \vastewater systeln. The draft rule addressed the role of the ""satellitc....
comlnunities and their collection systelns as \vell as the regional systenl. Satellite
co.nlnunities Inay \velJ becollle joint pennittees and subjcct to the saIne NPDES regulatory
requ irements.
If subject to an enforcelnent action as a co-pennittee.. the cOlnnlunity could receive
adlninistrative orders to be part of a ('onsent Decree.. as is currently happening to Duluth..
Minnesota. The City of Duluth is a co-pennittee of the collection systenl \vith the Western
Lake Superior Sanitary District. In 2002.. the City and District negotiated vvith MPC'A to
nnalize the ternlS ofa new five-year pernlit to operate the collection systeln. As part of the
pemit conditions.. Duluth agreed to a c0l11pliance schedule to control and eli.ninate SSOs
where intlo\v and intiltration fro.n thc city"s collection systenl \vas the prilnary cause.
Unfortunately.. SSOs actually increased in 2003 versus the prior t\\'o years.. partly attributable
to mechanical and operational fai lures on the District" s systenl.. and not just \vet weather
tlow. This caught the attention of the U.s. EPA and on January] 2.. 2004 the city of Duluth
and the Western Lake Superior Sanitary District received an adlninistrative order requiring
the city and the district to furnish inforlllation and develop a plan of action relative to
eliminating SSOs. The city and the district 111USt SUbl11it the plan of action to the U.S. ErA b)
May 14~ 2004 as the starting point tor entering into a Consent Decree to elilninate SSOs.
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Regional Cost Estimates
Expanding the conveyance and treatrnent tàcilities enough to elinlinate the risk of an
overtlo\v is not practical or feasible. The prinlary lirllitation is the need to double the capacity
of the Metro Plant \vhere peak tlo\v rates could reach over 1.3 billion gallons per day'. 1'0
understand the relative cost of conveying and treating excessive 1/1.. capital costs \verc
estirnated based on assurning a 25-year stonn event occurred \vith the forecasted
developrnent of 2030. Technically.. the interceptor systenl rllust not be overloaded f(]r any
raintàll condition so using a 25-year event is for cornparativc purposes only. (~apital cost for
treatrnent plant capacity \vas also estirnated. 'The cost of increasing the hydraulic capacity' of
each plant was not estirnated because of the lirnitations of space at each site.
Total capital costs based on the 25-year 1/1 event.. for MC'ES conveyance and treatrnent
facilities needed for ultirnate developrnent.. \vould approach a halfbillion in 2002 dollars. If
sized for the ultinlate service area.. the cost of these tàcilities \\/ould be even greater. 'The high
cost of expansion to convey 1/1 only provides a nlcasure of ho\v irllportant 1/1 reduction is as
it is not feasible to construct facilities large enough to prevent an SSo.
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Alternatives Considered
Regional versus Local Solutions
Metropolitan Council Environlnental Services~ as the NPDES pennit holder~ nlust take action
to reduce the risk of an overtlo\v froln its interceptor systeln. rrhe t\\/o basic options
considered by the Council \vere I) to increase the systeln capacity~ or 2) require that satellite
cOlnlnunities reduce the III rates entering their collection systenls. Infonl1ation presented to
the III Task Force supported the Counci I staff position that increasing systeln capacity to
handle III \vas not a viable option. The task force Inelnbers agreed that reduction of III is the
only long-tenn option that allo\vs for efficient aCCOlllll1odation of regional gro\vth and
reduces the risk of san itary se\ver overtlo\vs.
Means of Enforcement
Several strategies on how to reduce III in the region \vere discussed by the III rrask Force.
One of the key issues discussed was ho\\' prescriptive MC'ES should be regarding III
reduction. rrhe task force agreed that MC'ES should sinlply set III reduction goals and allo\\
each comlnunity to select the Illcasures that \voldd best Il1Cet those goals. rrhe role ofMC'ES
in this approach is to provide technical assistance and serve as a focal point for
cOlnmunicating lessons gained froln custonler cOlnlllunities as they illlplelllcnt their prograllls
to reduce III.
Enfòrcelnent of the III goals could be accoll1plished through the existing ('olllprehensive
Planning Process. MCES currently revie\vs and approves local conlprehensive plans and
those plans could include the cOlnlllullity~s plan for Ineeting the III goal.
Other Options
MCES also could Inodit), the Se\ver Discharge Rules that currently address industrial
pretreatlnent. These rules could be expanded to address excessive III and prohibit excessive
III froln each cOlnlllunity.
Other regional sewer districts use cOlnlllunity contracts to linlit the peak flo\vs froln
custolners. Such contracts could establish a plan for reduction of peak flows over tilne to
Ineet the 1/1 goals.
As the ne\v federal regulations are ill1plell1ented" MC'ES could require custolller COnlll1Unities
to becollle co-penllittees under the NPDES pennit progralll. Under the perlnit conditions.. the
penllittees would cOlnll1it to elilninating excessive III. A pennit violation could lead to a fine
and Inu Itiple violations cou Id result in a court ordered consent decree that Inandatcs
correcti ve action.
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Financial Incentives
Funding of the progralTIs to reduce 1/1 is a signiticant concern for local governnlent. l~he
option of collecting additional revenue tì'onl all COnll11Unities under the current rate charge
and distributing it under a surcharge progranl \vas judged by the task force to be unt~lir to
those cOlTIrTIunities now rTIeeting the 1/1 goal. ('ouncil staffforrnulated an approach to collect
additional revenue frolTI cornnlunities \vith excessive 1/1 and then use this revenue to support
a 50/50 match progralll tor 1/1 reduction. rrhis approach" labeled as a COllllllun ity Assistance
....Surcharge".." establishes a rllinilllulll account in these cOITIrnunities tor 1/1 reduction.
An alternative tinancial progranl \vas suggested by task force nlenlbers: rather than pay
MCES the additional funds and receive thern back under a 111atching progral11" S0l11e
COmlTIUn ¡ties could choose to "()pt-out" (undel1ake voluntary 1/1 reduction progranls that are
funded at the SalTIe or greater level). LInder this approach" a cOlnnlunity \vould obligate local
funds to undertake the sallle or greater effort tor 1/1 reduction.
A financial penalty or "·Dernand ('harge.... tor not 111eeting the 1/1 goals \vithin a specified tirlle
was discussed as another rneans of assuring conlpl iance. COITIlnunities that cOlltinue to have
excessive 1/1 could not continue to discharge the excessive peak 11o\\'s into the interceptor
systelTI. The cost to MC'ES to control the peak tlO\V and provide flo\v attenuation at the point
of connection vvould be assigned back to the COITIITIunity as a DelTIand Charge.
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Authority, Conclusions and
Recommended Actions
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Authority
The Metropolitan Council is directed by Minnesota Statutes~ Section 473.145 to prepare a
cotnprehensive developt11ent guide for the t11ctropolitan area. ~rhe developlnent guide~ as
currently ilnplelnented~ consists of the 2030 [)el'elofJlllelll I~~ra/lle\t'()rk and four ~~systeln
plans~~ dealing \vith transportation~ aviation~ waste\VateL and regional recreation open space.
Minnesota Statutes.. Section 473. J46 provides direction to the ('ouncil to adopt these
cOlnprehensive policy plans for transportation.. airports.. parks and open space~ and
w'aste\vater treatlnent as chapters of the develoPlnent guide. T'he developlnent guide
legislation also alJo\vs for the Council"s adoption of related policy statelnents~ goals~
standards~ progralns and Illaps describing ho\v it \vill achieve its charge. It is \vithin this
context that the Council is preparing the update to its existing ¡Valer Resources Afal1o(p;e/llenl
P()li(~\' Plan that \vas adopted in Decelnber 1996. 'fhe revised Plan will contain the
was t e wa t e r ~.. s y s t e 111 p I a n ~ ~.. p lu s po I i c i e sin 0 vera II \v ate r qua lit y ~ non - po in t so u rc e po II uti 0 n
controL and \vater supply.
Legislation related to Inetropolitan land-use planning (Minn. Stat. Sec 473.858) suggests that
cornprehensive plans of local governlnents cannot be in conn ict \vith the Inetropol itan systenl
plans for airports.. transportation.. \vaste\vater~ and regional recreation open space. 'fhe s)'stenl
plan for Inetropolitan \vaste\vater service \vill occur \vithin the updated ~I/aler R(!sourc(!s
Manage/11enl Poli(\' Plan.
In a sirnilar Illanner" the C\)uncil"s 2030 Del'elojJ/J/enl f-',.(lIJ/e\t'ork establishes a gro\\th
Inanagelllent strategy that incorporates systelll plans into overall regional developlnent. Both
the update to the Waler Resources l\Ialla(p;elllenl [)0Ii(1' fJlall and the 2030 DevelojJl71enl
Franlelt'ork \vi I J be used to detenn ine consistency of local governlllent plans \\'ith those of
the Metropolitan ('ouncil. Material contained in the plans can be used to detennine \vhcthcr
there is a substantial impact or a substantial departure 1'rol11 the Inetropolitan SystCll1S plans.
The ('ounci I intends to adopt its peak hourly design standards as part of the ¡,r'aler Resources
lvlanagenlenl Poli(v Plan. These standards are the basis for the design of the Metropol ¡tan
[)isposal Systeln and \vill be used to establish 1/1 goals for each of the COllllllunities served by
the Metropolitan Disposal Systeln (MDS). ('0J11111Unities \vill be asked to develop an 1/1
reduction plan to reduce their peak hourly tlows to Ineet these design standards. Those
comrllunities that discharge flows into the M DS at rates higher than the design standards put
the system at risk of overtlo\vs and~ therefore~ have a substantial il11pact on the MDS.
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Conclusions
The Council staff and the III Task Force ITIelTIbers conclude that:
· The capacity of regional \vaste\vater conveyance and treatlTIent facil ities is being exceeded
during sign i ficant rai n falls because of excess ive in fi Itrationli n flovv' (III).
· Excessive III has used up existing capacity for future gro\vth.
· Overloaded \vaste\vater conveyance and treatlTIent facilities have resulted in unacceptable
conditions such as private property danlage~ spills and sanitary sevvcr overflov~ls (SS()s).
· MCES" as the regional wastewater utility and NPDES penTIittee~ ITIUSt take action no\\/ to
reduce the risk of overloading the regional \vaste\vater facilities.
· It is not feasible to enlarge MCES ~s facilities to accolllnlodate all the III fronl tributary
corTImunities.
· MCES has a fiduciary responsibility' to not expend funds to convey and treat clear \\'ater
frOITI illegal connections associated \vith private property sources such as SUI11P pUI11pS and
rain leaders.
· The M(~ES design allo\vance for III in the interceptor s)'stenl is reasonable as l11any local
COITIITIUn ities ITIeet th is standard.
Recommended Actions
The Task Force recomnlends that the Metropolitan ('ouncil adopt the following III policy
statements and corresponding ilTIplenlentation strategies for inclusion in the next 1'llaler
Resources ~lanageJllenl Poli(l' Plan.
III Policy Statements
The Metro/)()Iilan C10uncil H'ill eSlahlish 1/1 <'2",oa!.",fÓr all COJl1Jlll1nilies (lischarlf,in<'2",
1vaste11'ater to the Metro/Jolitan Di.\jJosal .~~l'sleJJ1, (1oJJ1J1111nilies Ihal have excessive I/} in
their .\'anitalJ) seH'er .\)'SleI11S H'ill he require(llo eliJJ1inale the excessive 1/1 H'ilhin a
reasonahle I iJlle /JerÙ)(1.
The lv!etro!Jolitan C"ounciI11'ill nOI/JrovÙle (ul(lilioJ7al ca/Jaci(l' 11'ithin ils interce/Jlor
.\~vsteI11 to serve excessive 1/1.
Implementation Strategies
The Metropolitan ('ouncil \vill:
1. Continue to use the current design standards for interceptors.
2. Requ ire corTI ITI un ities served by the M DS to inc lude an III progranl \vith in thei r next
cOI11prehensive plan.
3. Develop III goals for all COnllTIUnities as \vell as guidelines for the preparation of the
local III progranlS.
4. Require the COITIITIunity to reduce its III to reach the design flo\v standard f()r each
connection point to the MDS \vithin a five-year period frol11 the adoption of its
comprehensive plan.
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5. Measure peak inflovv during \vet \veather conditions by either the MCES ITIetering
system or by telTIporary ITIonitoring equipl11cnt installed in the sanitary' sc\vcr SystCITI.
6. A. Initiate an 1/1 tinancial assistance surcharge progralTI'I starting in 2008. --rhis
progralTI will allow' MC"ES to surcharge C0l11111unities to collect revenue tor the
c0l11munity to use for solving its III problel11.
B. Allow cOlnl11unities \vith 1/1 reduction in place to continue \vith their progralns and
not participate in MCES"s surcharge prograln. rrhis \vill allow cOITIlnunities to
undertake activities for III reduction using local funds.. as long as those funds are
equal to or greater than the surcharge progralTI funds.
M C E S will w 0 r k w' it h co 111 IllU nit i e s \\1 it h e it her 0 p t ion (A 0 r B) to he I p so I vet h e i r I I I
probleln on a case by case basis.
7. LilTIit increases in service \vithin those cOlnlnunities \vhere excessive 1/1 jeopardizes
MCES'Is ability to convey \vaste\vater \vithout an overtlo\v occurring. MC"ES \vill
work with those cOlnlnunities on a case by case basis.
8. Lilnit future increases in service \vithin those cOlnlnunities that have not Inet their 1/1
goal(s)' starting in 2015.. until the problenl is solved. MC'ES \vill work \vith
cOlnlTIunities not Ineeting goals on a case by case basis
9. Institute a \vaste\vater rate dellland charge progralTI.. starting in 2015'1 for those
comlnunities that have not ITIet their 1/1 goal(s).. and are not actively working to do so..
to help defray the cost of providing attenuation \vithin the MDS to recover the capacity
lost to their excessive III. MC"ES \vill continue to revie\v COll1111Unities and \vork \vith
theln on a case by case basis.
10. Work with the Public Facilities Authority to 111ake funds available for III
ilTIprovelnents.
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