8. Sewer Rehab report ,,p--,
II :.„
CiTY OF
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II t CHANHASSEN
`� _ - _ 690 COULTER DRIVE • P.O. BOX 147 • CHANHASSEN, MINNESOTA 55317
II �'''7 (612) 937-1900
1 MEMORANDUM i V . ,
TO: Don Ashworth, City Manager
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I FROM: Gary Warren, City Enginee ;;,,., - .. - ..
DATE: April 5 , 1989 °� - - --
IISUBJ: Accept Sewer Rehabilitation Report j..,_:
File No. PW200
Over the past several years , the Metropolitan Waste Control
Commission has chosen to single out Chanhassen as a prime example
II of a sanitary sewer system in need of repair for the elimination
of infiltration and inflow ( I/I) to the system. While we may
take exception with the degree of the problem, there is no
1 question that the older portions of the City which were largely
constructed of clay tile pipe are in need of repairs . The City
has budgeted $150 , 000 in this year ' s Sewer Expansion Fund (Fund
No. 401 ) for embarking on the first year of rehabilitation .
IIThe first step in arriving at the rehabilitation program was to
televise 40 ,000 feet of the older portions of the sanitary sewer
II system to identify and make general recommendations concerning
the defective sewer pipes. This was done late year 1987 and the
results of these investigations were evaluated and compiled by
II BRW in the attached report. The purpose of this report is two-
fold. In addition to providing specific recommendations on the
individual sanitary sewer segments, it also is instrumental in
establishing a rehabilitation dollar value for the total program
I such that the City can now budget for an annual commitment for
the sanitary sewer rehabilitation. In many cases , sewer rehabi-
litation of this nature goes hand-in-glove with a pavement reha-
bilitation program. Indeed, this may be the case for some of the
sewer segments identified in this report. In all practicality,
if over three spot repairs are required for a city block, the
II roadway surface will typically be tore up significantly such that
the entire roadway surface should be considered for replacement.
The attached report therefore will serve as a guide for us in
I prioritizing the sanitary sewer rehabilitation program. Based on
the total need identified by this report, it would be my recom-
mendation that a annual commitment of approximately $150 ,000 be
IIbudgeted for embarking on this program. I hasten to point out
II
1
Don Ashworth 1
April 5 , 1989
Page 2
that from an infiltration/inflow standpoint, rehabilitation of
the municipal sanitary sewers addresses only one important aspect
of the City ' s problem; however , the City needs to also undertake
a private source removal program, i .e. sump pumps and drain tile
connections in order to effectively deal with the total I/I
problem.
It is therefore recommended that the attached Sanitary Sewer
Study dated March, 1989 prepared by BRW be accepted as a rehabi-
litation guide for the City ' s sanitary sewer system and that
staff be directed to inaugurate the first year ' s reconstruction
program in accordance with the present $150 ,000 budget commitment
for 1989 . It is futher recommended that the City Council
establish an annual funding commitment in the City ' s Sewer
Expansion Fund for completing the rehabilitation of the sanitary
sewer system as outlined in the report.
Attachment 1
1 . Sanitary Sewer Rehabilitation Study.
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