HomeMy WebLinkAboutReview of 1983-1985 Sewer System Evaluation Reports Prepared for Mamaroneck Sewer District 2/1/1986 111.
Engineering
Report
Review of
1983-1985 Sewer System Evaluation Reports
Prepared for Mamaroneck Sewer District
For
Town of Mamaroneck
New York
February 1986
MPI Project No . 849-02-6103
PIRNIE
ve-
4
TABLE OF CONTENTS
SECTION PAGE
1. 0 INTRODUCTION 1
2 . 0 TOWN OF MAMARONECK SEWER SYSTEM 1
3 . 0 METHODOLOGY FOR THE DETERMINATION OF
INFILTRATION/INFLOW 2
4 . 0 INFILTRATION/INFLOW WITHIN TOWN OF
MAMARONECK SYSTEM 3
5. 0 SEWER SYSTEM HYDRAULIC DEFICIENCIES 6
6 . 0 OVERFLOWS, BYPASSES & LOCAL SEWER PROBLEMS 8
7 . 0 PROJECT FINANCING 8
8 . 0 CONCLUSIONS 9
9 . 0 RECOMMENDATIONS 12
APPENDIX A - WORK SUMMARY AND COST ESTIMATES A-1
TABLES
1 Excessive I/I , Town of Mamaroneck 4
FIGURES
Following
Page
1 Excessive Infiltration/Inflow Mini-Area Map 4
1.0 Introduction
This report, which was prepared at the request of the Town
of Mamaroneck, is a review of the proposed program of
improvements to the Town' s sewer system which was recommended
by others in the 1983-85 Sewer System Evaluation Reports
prepared for the Mamaroneck Sewer District.
The flow information and cost data used in this report was
derived from the following studies :
- Sewer System Evaluation Survey (SSES) Cost Effectiveness
Analysis, Mamaroneck Sewer District, Volume 1, Main
Report, prepared by O'Brien & Gere, October, 1983 (1983
Report) .
- Facilities Planning, Mamaroneck Sewer District, Sewer
System Rehabilitation, Phase 1 Report, prepared by
Blasland and Bouck Engineers, April, 1985 (1985 Report) .
Since these Reports were completed, the cost data was
updated to include more detailed construction estimates and to
reflect anticipated funding (without grandfathering) as set
forth by the New York State Department of Environmental
Conservation (NYSDEC) in its September 25, 1985 letter to
Westchester County. These costs are summarized in Appendix A.
The costs presented in this review reflect the revised costs to
the greatest practicable extent.
The Town requested further study of the proposed sewage
pump station and force main project at Baldwin Avenue.
Additional alternatives were examined and rejected as not
cost-effective . It is anticipated that the evaluation of these
alternatives as well as the entire proposed Town sewer
improvement program and funding considerations will be
discussed at a Town Board meeting on March 5, 1986.
2 . 0 Town of Mamaroneck Sewer System
The Town of Mamaroneck, located in the southwestern
portion of the Mamaroneck Sewer District (District) , presently
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owns 11 percent of the District Sanitary Sewer System (32 of
282 miles) , spread out over an area of approximately 3 . 10
square miles . The sanitary sewers , which are predominantly
vitrified clay pipe, range in size from 8-inch to 24-inch
diameter. With the exception of 3 County-owned pump stations
(Saxon Woods Pump Station, Fenimore Road Pump Station and
Weaver Street Pump Station) and the Town-owned pump station on
Kolbert Drive (which will be eliminated in conjunction with
sewer installation at the Fenbrook subdivision) , most of the
sewage flow is transported by gravity sewers via the
County-owned interceptor to the Mamaroneck Wastewater Treatment
Facility located in the Village of Mamaroneck.
3 . 0 Methodology for the Determination of Infiltration/Inflow
The methodology for determination of Infiltration/Inflow
(I/I) utilized in the Reports was based on the classical
approach of obtaining flow measurements under varying flow
conditions (average, peak & minimal flows) and varying seasonal
fluctuations (normal, dry & wet weather) and comparing these
measured flows with expected sewer performance under the
following flow conditions :
"A" - Average Base Flow (domestic plus commercial/industrial
contributions)
"B" - Peak Base Flow (Average Base Flow x Peaking Factor)
"C" - Peak Dry Weather Flow (Peak Base Flow Including
Infiltration)
"D" - Peak Wet Weather Flow (Peak Base Flow plus Cost-Effective
Peak Infiltration plus Peak Inflow)
To determine the relative contribution of I/I , the
District was sub-divided into 27 regions, referred to as
mini-areas, 9 of which were located in the Town of Mamaroneck.
Key manholes, located at the downstream end of each mini-area,
were used for obtaining flow measurements.
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Sections of sewers within each mini-area which failed to
meet flow conditions under "A" and "B" were designated for
replacement without performing a cost-effective analysis .
Mini-areas with sewer sections which failed to meet flow
conditions under "C" and "D" were designated as having
excessive infiltration and inflow, respectively. These
mini-areas were further analyzed by comparing the costs of
reducing I/I by rehabilitation of the sewers with the costs of
transport to and treatment at the Mamaroneck Wastewater
Treatment Facility.
Once the I/I problem areas throughout the District were
located and defined, unit costs ($/gpd) were developed for each
source based on the amount of I/I that could be removed for
each respective location. Locations were then combined in the
order of increasing unit costs , and a cost-effectiveness
analysis was performed to determine at which locations
rehabilitation would be less costly than providing a given
degree of treatment for these flows at the Mamaroneck
Wastewater Treatment Facility.
4 . 0 Infiltration/Inflow Within Town of Mamaroneck System
Mini-areas within the Town of Mamaroneck, designated to
have excessive I/I are presented in Table 1 and shown on Figure
1 (Figure 9 of the 1985 Report) . The majority of mini-areas in
the Town were determined to have excessive infiltration and all
of the mini-areas exhibited excessive inflow. An analysis of
flows , based on information obtained from the 1985 Report, for
the Town of Mamaroneck is presented below:
Average Base Flow: 1. 13 mgd
Peak Sanitary Base Flow: 2. 37 mgd (Based on a Peaking
Factor of 2 . 1)
Infiltration: 2 . 30 mgd
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TABLE 1
EXCESSIVE I/I , TOWN OF MAMARONECK
Excessive Excessive
Mini-Area Designation Infiltration Inflow
S1 (Portions) X X
S2 X X
SE1 X X
SE2 (Portions) X
SW1 (Portions) X X
T1 X
T2 X X
T3 • X X
T4 X X
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\ ( `; ''� ii LEGEND
II
' �' \``�` DISTRICT BOUNDARY
�• ` M2 .� r -- -... . _ MUNICIPAL BOUNDARY
L
MW2 \ \\�:31, _- ROADWAY
WI-111X. PLAINS .1,, "` \ — — — MINI - AREA BOUNDARY
-. /� �4-, / .\ EXCESSIVE INFLOW
\z,, �,� MINI-AREA
- \ �k?///%' / • ( ( EXCESSIVE INFILTRATION
`'••'\ MW I \ BB4 E I ( I MINI —AREA
WC ,' .
J� S�n�aSD4LE EI �.r R rr'' B.
� / BSI // -
SW2 r BB2"
�- SE2 ( , //HI �--
FACILITIES PLANNING
k ` =`V2�'�� R YE
�- rc�v,' ` ` I ,`ILL" L' BI MAMARONECK SEWER DISTRICT
\/1,1,, ,, i 'f i ;slAl'r1AEZ ��ya—+�ei '?
( I\ /
r'
T::::::
C
r;OrCHELLF Tis• INFLOW MINI - AREA MAP
/, HORIZONTAL SCALE IN FEET
, /A
6000 0 6000'
ly//
4 r:7:7r4"-'"' ""--4_—___ I
/-\,i--) Z7-7--..-7-P11A.1AP.-i 0. rr�trrK
/ .. .....�..__.. r.c.
9 •
Inflow -
Private/Unidentified: 14 . 94 mgd (Based on a 2-yr. , 24-hr
Public : 8 . 55 mgd design storm)
Areas where improvements for the removal of infiltration
are recommended as cost-effective include:
- Area located west of the Village of Mamaroneck, east of
Weaver Street (Rt. 125) and south of Rockland Avenue.
- Area located north of Rockland Avenue in the vicinity of
• Bonnie Briar Golf Course.
- Area northeast of Fenimore Road, except for the Murdoch
Woods development.
The recommended corrective work for infiltration removal
as described in pp. 1 and 2 of 11 in Appendix A includes the
testing and sealing of joints in approximately 35, 000 if of
sewer and the rehabilitation and replacement of 110 manholes at
an estimated bid price of $343 , 400. On a unit cost basis, this
amounts to about $0 . 15/gpd. The total project cost including
contingencies, construction engineering, legal and
miscellaneous costs, and interest during construction, but
excluding design engineering, is estimated at $505 , 550 (see
Table MT-1 in Appendix A) .
Rehabilitation recommended for inflow correction as
described in pp. 3-10 of 11 in Appendix A consisted of:
Estimated
Bid Price
1. Testing & sealing of 3 ,000 if of sewers to
remove inflow from indirect connections $ 33, 600
2 . Installation of watertight frames & covers
for 677 manholes to eliminate surface water
from entering the sewers 269 , 700
3 . Raising 8 manholes to grade or above to
eliminate surface water from entering
the sewers 5 , 000
-5-
4 . Elimination of 6 direct storm sewer
connections to sanitary sewers
- Project 1T, (Edgewood Avenue)
eliminate 320, 000 gpd $ 4 , 200
- Project 2T, (Heather Lane)
eliminate 290, 000 gpd 80, 500
- Project 3T, (Senate Place & Damon
Terrace) eliminate 310, 000 gpd 177, 000
- Project 4T, (Rouken Glen East Drive)
eliminate 90, 000 gpd 32 ,500
- Project 5T, (Maple Hill Drive & Dante
Street) eliminate 150, 000 gpd 380
- Project 6T, replaced under County
Interceptor Project 2M --
Total $602, 880
The proposed public inflow correction of 8 . 55 mgd has been
estimated to cost $602, 880 (bid price) , or about $0 . 71/gpd.
The estimated total project cost as shown in Table MT-1 of
Appendix A is $888 , 000 .
5 . 0 Sewer System Hydraulic Deficiencies
There was only one reach of sewer that was determined in
the 1985 Report to be incapable of transporting the peak base
flow. The sewer runs along Baldwin Avenue between manholes
TC116 and TC113 . Due to both upstream and downstream localized
system problems, the 1985 Report recommended that additional
upstream and downstream reaches be included with the
replacement of the Baldwin Avenue sewer. Thus, the entire
length of sewer from manholes TC118 to TC1 was recommended for
replacement. Three alternatives were evaluated and the
following bid prices estimated:
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• o
1. Project 1T-1
Construction of 3-mgd Pump Station with relief sewer.
2 , 050 if of New 12-inch Force Main
231 if of New 30-inch Gravity Sewer $1, 310, 000
2 . Project 1T-2
Construction of 3-mgd Pump Station with relief sewer
1, 000 if of New 12-inch Force Main
•
1,150 if of New 30-inch Gravity Sewer $1, 500, 000
3 . Project 1T-3
3 ,515 if of New 30-inch Gravity Sewer $2, 443, 000
According to the 1985 Report, Project 1T-1 (described on
p. 11 of 11 in Appendix A) was most cost-effective and
therefore the recommended alternative .
At the request of the Town, the County instructed its
consulting engineers to investigate additional alternatives to
the recommended pump station and force main. These included:
1. Diverting flow above Baldwin Avenue to the New Rochelle
Sewer District (NRSD) , bypassing the Fifth Avenue Pump
Station.
2 . Diverting flow at Baldwin Avenue to the NRSD via the Fifth
Avenue Pump Station.
3 . Diverting flow above Baldwin Avenue to the County Trunk
Sewer in Lakeside Drive.
4 . Constructing a holding tank for excess flow.
The results of the investigations indicated that the
recommended pump station and force main is the most cost-
effective project. We concur with this conclusion.
The estimated total project cost of the proposed project
as shown in Table MT-1 of Appendix A is $2, 249 , 450 .
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6 . 0 Overflows, Bypasses & Local Sewer Problems
The 1985 Report identified three non-permitted overflows
and one permitted overflow in the Town of Mamaroneck. These
overflows occur during periods of increased inflow and
infiltration. Each of the overflows will be evaluated upon
completion of the rehabilitation program to determine if they
should be eliminated. The Report does not state who will
perform the evaluation.
The 1985 Report identified three major problem areas
within the Town of Mamaroneck which are subject to surcharging
and flooding during periods of increased inflow and
infiltration.
The East Brookside Drive interceptor, which is a
County-owned sewer, will be replaced with a new sewer,
eliminating the problem in this area.
The Palmer Avenue area, which extends from manhole TC118
to manhole TC1 along Baldwin Avenue, will be relieved of its
localized problems , when this reach of sewer has been replaced.
However, the 1985 Report notes that private inflow is a
significant factor in this area and recommends that the Town
actively pursue elimination of same.
Relief from surcharging , experienced in the Ferndale Road
area is also expected with the removal of infiltration and
public inflow from the sewer lines tributary to this area .
7 . 0 Project Financing
The Town of Mamaroneck will incur costs for rehabilitation
of the Town' s sewers and will be assessed its fair share of the
cost to rehabilitate County interceptors .
A breakdown of the Town' s allocated project cost for
fixing the Town' s sewers based on anticipated project funding
(without grandfathering) as set forth in NYSDEC' s September 25,
1985 letter to the County is presented in Table MT-2 of
Appendix A. As shown in the footnotes to Table MT-2, for I/I
Correction and Major Rehabilitation Projects , the Town must pay
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15 percent of costs eligible for Federal and State funding plus
all ineligible costs for interceptor sewers , 45 percent of
eligible costs plus all ineligible costs for collector sewers ,
and all costs other than disconnecting and/or plugging for
removal of direct connections.
8 . 0 Conclusions
The Reports utilize classical approaches for determining
excessive infiltration/inflow. The criteria for cost-
effectively selecting which mini-areas within the District
should be rehabilitated are discussed in depth in both reports .
Rehabilitation costs for infiltration removal and public
inflow correction are based on widely accepted standard
techniques for reducing and/or eliminating I/I from manholes
and sewers.
As shown in Table MT-1 of Appendix A, the total project
cost, less design engineering, is estimated as $3, 643, 000 in
September 1987 dollars. The Town share of this amount is
$1,546 ,725 . Using EPA-accepted bonding periods and rates (30
years, 10 . 5 percent) , the annual Town share for fixing the
Town' s sewers is estimated at $171, 100 . The Town' s share of
County rehabilitation work (not included in Appendix A) was
estimated in the 1985 Report to be $16 , 500 annually.
The projected Engineering News-Record Construction Cost
Index of 4 , 665 referred to in Table MT-1 appears to be the
20-cities Average value. Costs in the New York area could be
about 20 to 25 percent higher.
Despite the fact that the Town owns only 32 of 282 miles
of sewers in the District, the Town has incurred the highest
costs, on a municipality basis , for improvements to its sewers .
A breakdown of these costs as shown in Table MT-2 of Appendix A
is presented below:
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-ammo
Total Project Cost Town Share
Infiltration Reduction $ 505 , 550 ( 13 . 9%) $ 236 , 965 ( 15 . 3%)
Inflow Reduction 888 , 000 (24 . 4%) 644 , 585 (41. 7%)
Sewer Replacement 2 , 249 , 450 (61. 8%) 665 , 175 (43 . 0%)
$3 , 643 , 000 $1, 546 , 725
The I/I reduction costs are reasonable, however , the
preliminary costs for sewer replacement will require further
refinements .
The sewer replacement cost, which accounts for 62 percent
of the total cost (43 percent of the Total Town share) , was
designated for corrections to hydraulic deficiencies along
Baldwin Avenue. Three alternatives were evaluated to correct
this stretch of sewer, and the final cost was based on the
first alternative , which included a 3-mgd pump station, 241 If
of replacement sewer and 2 , 050 if of force main. A breakdown
of estimated bid prices for the selected alternative is
presented in the 1985 report .
A review of the cost items included in the breakdown
indicates that costs are generally reasonable. The cost for
excavation (including spoils hauling) at $150 per cy appears to
be high. However, a more precise evaluation of cost for this
item would have to be based on the type of soils and ground-
water conditions encountered. The cost of the 3-mgd pump
station is estimated at $538 , 000. This cost could also vary
depending on site-specific conditions , such as soils and
groundwater conditions, structure size and type of mechanical
and electrical equipment provided in the station. A station
being furnished with comminutors, bar racks, an emergency
standby generator and a separate structure for a wet well and
dry well will be significantly more expensive than a station
that is provided with submersible pumps without any auxiliary
equipment.
For the cost-effectiveness analysis, the 1985 Report
assumed that the Mamaroneck Wastewater Treatment Facility will
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be upgraded to a secondary level of treatment. Due to the
severity of I/I within the Town of Mamaroneck, there would be a
slight or no change in the conclusions reached in the Report,
should the Facility not be upgraded to a secondary level of
treatment.
Areas requiring sewer replacement as a result of hydraulic
deficiencies , along with those areas experiencing localized
sewer problems, overflows and bypasses, have been discussed in
great detail. A program of proposed improvements has also been
adequately defined.
The 1985 Report concluded that it is cost-effective to
remove 2.1 mgd of the District' s total identified infiltration
(13 .3 mgd) at a bid price of $1, 190, 000 (Town Bid Price =
$343, 400) . Despite the fact that it is considered
cost-effective to remove the infiltration, the Report points
out that studies by O'Brien & Gere had shown that migration of
the infiltration in newly rehabilitated systems greatly reduces
the effectiveness of the rehabilitation program, since the
infiltration finds its way back into the system via a leaking
sewer at another location. In older sewer systems , like that
of the Town of Mamaroneck, where sewers consist mainly of
vitrified clay pipe, it is questionable whether in-line
infiltration can be effectively removed by correcting only a
portion of the sewers as recommended in the Report.
The 1983 Report established the District-wide private
inflow source contributions, based on the extrapolation of the
Siphon Area Building Inspection Program results and similar
SSES program. Extrapolation of results obtained in the Siphon
Area were used to estimate the numbers and types of private
inflow sources in each mini-area and the costs involved in
locating and correcting those sources. The public inflow
reduction program, which aims at reducing 40 percent or 8. 55
mgd of the total inflow in the Town of Mamaroneck, may not meet
its goal if the extrapolation based on the Siphon Area Building
Inspection Program (40 percent inflow and 60 percent private
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inflow) overestimates actual public inflow for the Town of
Mamaroneck. On the other hand, the public inflow may actually
constitute a greater percentage than estimated and the results
of the program may produce a greater reduction of inflow than
expected.
9 . 0 Recommendations
The principal conclusions of the 1985 Report should be
applied to any sewer rehabilitation that the Town adopts as
part of the District Sewer Rehabilitation Program.
In the interim, additional studies should be conducted in
the following areas :
a. Sewer Replacement Cost Update
The preliminary engineering cost estimates prepared for
the recommended sewer replacement for the Town of
Mamaroneck should be updated to include consideration of
site-specific data such as soils and groundwater
conditions and pump station design requirements . The
site-specific conditions and type of pump station selected
may reduce overall sewer replacement costs and the
corresponding share of costs to be borne by the Town.
These estimates are being updated by the County ' s
consulting engineers and the final design will be based on
input from the Town.
b. Investigation of Migration of Infiltration
A review should be conducted of past research performed
for the 1985 Report and for other projects concerning the
impact of infiltration finding its way back into the
system on the effectiveness of the rehabilitation program_
This will clarify the cost-effectiveness of the testing
and sealing projects estimated at a bid price of $223 , 700.
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c . Modifications of Sewer Ordinance
The Town should develop, in conjunction with the County ,
modifications of the current sewer ordinance to include
provisions for the removal of private inflow.
d. Review of Local Sewer Maintenance Program
Existing local sewer maintenance programs should be
upgraded to include provision for effectively reducing I/I
from local sewers . Consideration should be given to
reviewing similar programs in neighboring systems and
training existing staff in rehabilitation methods for
manholes as a potentially less costly approach than using
outside contractors . We do not believe Federal or State
funding is available for these training programs . In
November 1984 , the U.S . Department of Housing and Urban
Development, Office of Policy Development and Research
published a manual entitled Utility Infrastructure
Rehabilitation which offers information on rehabilitation
techniques . The 1985 Report also contains a description
of these techniques .
e. Review of Drainage Projects for Potential Benefits to I/I
Reduction
Proposed drainage projects and drainage problem areas
should be reviewed to determine the need for certain I/I
reduction projects if drainage problems are solved. For
example, lowered water tables and reduced ponding
resulting from improved drainage should reduce I/I to
sanitary sewers . On the other hand, improvements to
sanitary sewers in areas with inadequate drainage could
raise the water table and exacerbate drainage problems .
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APPENDIX A
SCHEDULE "B"
WESTCHESTER COUNTY
MAMARONECK SEWER DISTRICT
SEWER SYSTEM REHABILITATION
WORK SUMMARY AND COST ESTIMATES
TOWN OF MAMARONECK
OCTOBER 1985
BLASLAND & BOUCK ENGINEERS, P. C.
244 WESTCHESTER AVENUE
WHITE PLAINS, NEW YORK
. e
. TABLE MT-1
WESTCHESTER COUNTY
MA1IARONECK SEWER i15TRICT
SEWER SYSTEM REIIAfIIITATlON
PROPOSED WORK W TLINC ANT! COST SUMMARY
TOWN OF MAMARONECK
Pipe Eligible Costs2 Total Costs
Estimated Interest3
Rehabilitation Diameter length Quantity Estimated Construction Construction Legal i During 4
Work Ceteyory lechnlqun (in) (ft) fee.) Did Price Contingency Cost Engineering Misc. Construction Total Eligible Ineligible
Infiltration Test and Seal 8-15 35,000 -- $ 223,700 S 55,900 S 279,600 S 24,550 S 13,975 $ 11,705 S 379,330 $ 318,125 $ 11,705
Reduction
11/1
(1;1 Correction) Manhole Rehabilitation -- -- 110 . 119,700 79,900 149,600 13,150 7,475 5,995 176,110 170,725 5,99S
S 341,4(10 $ 85,800 S 429,200 S 37,700 S 21,450 S 17,700 $ 505,550 S 488,.150 $ 17,200
Indo.. Reduction Test and Seal 8-15 3.000 -- S 33,600 S 8,400 S 47,000 S 3,100 S 2,100 $ 1,650 S 49,450 $ 47,800 S 1,650
(i/I Correction) .
Replace Manhole Frame i Cover -- -- 617 769,700 67,600 137,100 79,600 16,800 13,500 397,100 381,700 13,500
Raise Manhole to Grade 4 -- -- 8 5,000 1,200 6,700 550 375 300 7,375 7,075 300
Replace frame 4 Cover
Disconnect Direct Cunnecttons5 -- 1,570 -- 294,580 73,')20 368,500 37,150 18,375 14,750 431,975 3,995 429,980
(S Projects)
S 602,880 5151,120 S 754,000 S 66,200 S 37,600 S 30,200 S 888,000 S 442,570 $445,430
SUBTOTAL (1/1) S 946,280 5236,970 51,187,700 $103,900 S 59,050 $ 47,400 51,393,550 S 930,920 $461,630
Major Sewer Replacement 12,30 2,300 -- 51,310,000 $117,800 $1,631,800 $144,150 $ 81,900 S 65,600 57,249,4506 $1,863,850 5385,6006
RehaDilltetion (1 Project)
Test and Seal -- -- -- _0 0 _0 0 0 0 -_ 0 0 0 ,
ShIIIOTAL (Major l 31,11(1,('00 3117,80Ii 51,617.8t'0 5144,150 $ 81,400 S 65,400 $1,149,4'.06 $1,863,8',0 3385,6(106
101A) COST 52,756,18l .5`_44,7;0 $2,421,a00 $14.1,.150 $140,450 $111,000 $1,641,(00(' s:,794,/70 $941,1196
1 • Prices are in Sept.•rgier 1987 dollars tori..-.ted ENA6t'I, 46.15).
7 - Costs eligible for Ie.lefel and/or NY .tete funding.
3 - )eligible. cost. •
4 - E4ual to Prnlrct Cast less lrs.yn Fngln-er n'g cost.
S - Cnlr ,»i', Is•.uc'ated w1'...,t1 (I scnnne. �.
t. n end/or (!.,.)ging of .lIrect eflans 4,. rynsr.ler..d -1Ig01VW.... .e• •ur•h 1, •VGP(( Iu 'he July 10VW. !erre' in vrstles•er lOMntr.
n
Ir.Tu ..
4.s I .J ,051.1 ar.J '4r'0 4t.,t (I Pr-),,t Wnrih "4M s"sts O5n- !,N,ie 15-', 14 . , r-peri 1.
•
TARE( MT-2
WESTCIIESTFR COUNTY •
MAMARONECK SEWER DISTRICT
SEWER SYSTEM RFIIANILITATION
FI IND I N(: SUMMARY
TOWN OF MAMARONECK '
Prnject Funding'
Total Costs Local Funding
Rehabilitation
• Work Category - Technique Eligible Ineligible Total Federal NY State Eligible InellgIble Total
Infiltration Reduction Test and Seal S 318,125 S 11,705 $ 329,330 $ 174,970 $ 0 1143,155 $ 11,205 S 154,360
(I/I Correction)
Manhole Rehabllltatlon 170,275 • 5,995 176,220 93,615 0 76,610 5,995 87,605
S 488,350 $ 17,200 $ 505,550 - $ 268,585 $ 0 $219,765 5 17,200 $ 236,965
Inflow Reduction • Test and Seal $ 47,800 $ 1,650 $ 49,450 $ 26,290 S 0 • $ 21,510 S 1,650 $ 23,160
(I/I Correction) •
Replace Manhole Frame i Cover 383,700 13,500 397,200 211,035 0 172,665 13,500 186,165
Raise Manhole to Crede i 7,075 300 7,375 3,890 0 3,185 300 3,485
Replace Frame i Cover
Disconnect Olrect Connections 3,995 429,980 433,975 2,200 0 1,795 429,980 431,775
(5 Projects)
S 442,570 $445,430 S 888,000 S 243,415 1 0 $199,155 $445,430 $ 6.44,585
•
SUBTOTAL (I/I) $ 930,970 5462,630 51,393,550 $ 512,000 $ 0 $418,920 1462,630 $ 881,550
Major Rehab!IIlmt.Inn Sewer R.Llaeemwnl SI,R61,85U $185,600 $7,749,450 $1,075,175 5559,150 $279,575 8385,600 $ 665,175
(1 Project)
lest end Seal 0 O 0 0 0 0 0 0
SUDTOIAL (major) $1,963,350 $185,600 s7,749,4r•0 $1,025,125 $550,150 5)79,575 $185,44 $ 665,175
TOTAL COST - $2,794,770 $848,710 11,641,000 $1,917,125 $55.1,150 S6nR,495 1848,230 81,546,725
1 - Anticipated projec! lun,Ji nq I,,,thnut 4rardfatt•erlm)1 as set fort!, by t1Y5('TC in the Sept.e•her t.m5 'eller to aeat•.h.s'er County la as follows for hath I/I ,:orrert,cc ,n•1 4ajor
Nrnabtli tat,on: AI Interceptor ,ewers • 551 and 3(16 of el, ible •:nsts :•Ce•! by fe•.e . I 'I r „el•a ' ••1 of et lbin ea,:: rt ii all
t y •., .r 1 ml br�';t.,[. au enc yes, .srect i ; L^ca• pare .•qu sl to 151 ,1
in. tq,ble costs; 91 Cvltertor sen.rs - 551 nl .1 1,1 w cos': fuode•1 hvrr•_er31 en + .,r ii ..0,,,r ^0.11 to .`1 . ,�lth;e plus 311 I..II'7,hie •'0 st s; '.) Ilirert tonne , protects -
only :441.5 associ ar ea wir', dI srnn,••ctinq an�t;..r ;ll uState Ind!„r r•ral sur 11
oging are ellgOble for ',r • „9
Ili:1 45
•
WESTCHESTER COUNTY
MAMARONECK SEWER DISTRICT
SEWER SYSTEM REHABILITATION
TOWN OF MAMARONECK
Project: I/I Correction
Program: Infiltration Reduction
Technique: Test & Seal
Description:
Approximately 35 ,000 feet of sanitary sewer with pipe diameters ranging from 8 to 15
inches, will be cleaned and televised with subsequent testing , and if necessary,
sealing of joints with a chemical grout.
Estimated Project Cost*:
Bid Price $223,700
Contingency 55,900
Construction Engineering 24,550
Legal & Miscellaneous 13,975
Interest During Construction 11 ,205
7) Total $329,330.
Amount Eligible $318,125
Amount Ineligible 11 ,205
Local Share
Eligible Portion $143,155
Ineligible Portion 11,205
Total $154,360
*Costs are in September 1987 dollars (projected ENRCCI 4665)
Pav, 1 of 11
10222/C5
WESTCHESTER COUNTY
MAMARONECK SEWER DISTRICT
17) SEWER SYSTEM REHABILITATION
TOWN OF MAMARONECK
Project: I/I Correction
Program: Infiltration Reduction
Technique: Manhole Rehabilitation ,
Description:
An estimated 110 manholes will undergo rehabilitation to reduce manhole infiltration:
This may include: 1) manhole reconstruction, 2) sealing of manhole wall , and/or
3) repair of manhole invert or benchwall , depending on the condition of the specific
manhole.
Estimated Project Cost*:
Bid Price $119,700
Contingency 29,900
Construction Engineering 13,150
Legal & Miscellaneous 7,475
Interest During Construction 5,995
Total 5176,220•
Amount Eligible $170,225
Amount Ineligible 5,995
Local Share
Eligible Portion $ 76,610
Ineligible Portion 5,995
Total $ 82,605
*Costs are in September 1987 dollars (projected ENRCCI , 4665)
rage i of 11
1U/?2/,.5
WESTCHESTER COUNTY
•
MAMARONECK SEWER DISTRICT
SEWER SYSTEM REHABILITATION
TOWN OF MAMARONECK
Project: I/I Correction
Program: Inflow Reduction
Technique : Test & Seal
Description:
Approximately 3,000 feet of sanitary sewer with pipe diameters ranging from. F to 15
inches will be cleaned and televised with subsequent testing , a► d if necessary,
sealing of joints with a chemical grout.
Estimated Project Cost*:
Bid Price $33,600
Contingency 8,400
Construction Engineering 3,700
Legal & Miscellaneous 2 ,100
Interest During Construction 1 ,650
Total $49 ,450
Amount Eligible S47 ,800
Amount Ineligible 1 ,650
Local Share
Eligible Portion $21 ,510
Ineligible Portion 1 ,650
Total • $23, 160
*Costs are in September 1987 dollars (projected ENRCCI , 4665)
• F'acle 3 of 11
10/22A5
•
WESTCHESTER COUNTY
MAMARONECK SEWER DISTRICT
SEWER SYSTEM REHABILITATION
TOWN OF MAMARONECK
Project: I/I Correction
Pro ram: Inflow Reduction
ec`f hnique: Replace Manhole Frames and Covers
Description:
An estimated 667 manhole frames and covers are to be replaced with a suitable
watertight equivalent.
Estimated Project Cost*:
Bid Price $269 ,700
Contingency 67 ,600
Construction Engineering 29,600
Legal & Miscellaneous 16,800 .
Interest During Construction 13,500
Total $397,200
Amount Eligible $383 ,700
Amount Ineligible 13 ,500 .
Local Share
Eligible Portion $172,665
Ineligible Portion 13,500
Total $186, 165
*Costs are in September 1987 dollars (projected ENRCCI , 4665)
• ('acln 4 of 11
10/22/!;5
4
WESTCHESTER COUNTY
MAMARONECK SEWER DISTRICT
SEWER SYSTEM REHABILITATION
• TOWN OF MAMARONECK
Project: I/I Correction
Program: Inflow Reduction
Technique: Raise Manhole to Grade and Replace Frame and Cover
Description:
An estimated 8 manhole frames and covers in lowlying/flood prone areas will be raised
to grade and replaced with a suitable watertight equivalent.
Estimated Project Cost*:
Bid Price $5,000
Contingency 1 ,200
Construction Engineering 550
Legal & Miscellaneous 325
Interest During Construction 300
Total $7 ,375
Amount Eligible $7,075
Amount Ineligible 300
Local Share
•
Eligible Portion $3,185
Ineligible Portion 300
Total $3,485
*Costs are in September 1987 dollars (projected ENRCCI , 4665)
d
Page 5 of 11
F
•
WESTCHESTER COUNTY
MAMARONECK SEWER DISTRICT
SEWER SYSTEM REHABILITATION
TOWN OF MAMARONECK
Project: I/I Correction
Program: Inflow Reduction
Technique: Direct Connection Removal - Project IT
Description:
This project involves the plugging of a catchbasin overflow outlet pipe which
currently discharges to a sanitary manhole located near the end of Edge,•rood Avenue.
In addition, it has been estimated that approximately 50 feet of storm sewer (pipe
diameter not yet determined) will be installed, discharing storm water to an existing
drainage area.
Estimated Project Cost*:
•
Bid Price $4,200
Contingency 1 ,050
Construction Engineering 455
Legal & Miscellaneous 265
Interest During Construction 210
Total $6,180
Amount Eligible $ 685 .
Amount Ineligible 5,495
Local Share
Eligible Portion . $ 305
Ineligible Portion 5,495
Total $5,800
*Costs are in September 1987 dollars (projected ENRCCI , 4665)
7
pa(p 6 or II
WESTCHESTER COUNTY
1 MAMARONECK SEWER DISTRICT
= SEWER SYSTEM REHABILITATION
• TOWN OF MAMARONECK
Project: I/I Correction
Program: Inflow Reduction
Technique: Direct Connection Removal - Project 2T
Description:
This project involves the disconnection and/or plugging of two catchbasin overflow
pipes which are currently discharging into a nearby sanitary manhole on Heather Lane.
In addition, approximately 450 feet of storm sewer and 1 catchbasin will be installed.
Estimated Project Cost*:
Bid Price $ 80,500
Contingency 20,200
Construction Engineering 8,840
Legal & Miscellaneous 5,020
Interest During Construction 4,030
l;r Total $118,590
Amount Eligible S 1 ,370
Amount Ineligible 117 ,220
Local Share
Eligible Portion S 625
Ineligible Portion 117,220
Total $117 ,845
*Costs are in September 1987 dollars (projected ENRCCI , 4665)
fi'u 7 of 1]
10/2?/P5
a
WESTCHESTER COUNTY
MAMARONECK SEWER DISTRICT
E SEWER SYSTEM REHABILITATION
TOWN OF MAMARONECK
Project: I/I Correction
Program:. Inflow Reduction
Technique: Direct Connection Removal - Project 3T
Description:
This project involves plugging of a catchbasin overflow pipe which currently
discharges into a nearby sanitary manhole. In addition, it has been estimated that
approximately 800 feet of storm sewer and 3 catchbasins will be installed on Senate
Place and Damon Terrace.
Estimated Project Cost*:
Bid Price $177,000
Contingency 44,400
Construction Engineering 19,440
Legal & Miscellaneous 11 ,040
Interest During Construction 8,865
h- Total $260,745
Amount Eligible $ 685
Amount Ineligible 260,060
Local Share
Eligible Portion $ 305
Ineligible Portion 260,060
Total $260,365
*Costs are in September 1987 dollars (projected ENRCCI , 4665)
Elrl(je is flf 11
IU!2 "s''
a
WESTCHESTER COUNTY
MAMARONECK SEWER DISTRICT
SEWER SYSTEM REHABILITATION
TOWN OF MAMARONECK
• Project: I/I Correction
Program: Inflow Reduction
Technique: Direct Connection Removal - Project 4T
Description:
This project involves the disconnecting and/or plugging of a catchbasin overflow pipe
which is currently connected to a nearby sanitary sewer line on Roueken Glen East
Drive. In addition , it has been estimated that approximately 220 feet of storm sewer
and 1 catchbasin will be installed.
Estimated Project Cost* :
Bid Price $32,500
Contingency 8,150
Construction Engineering 3 ,570
Legal & Miscellaneous 2 ,025
Interest During Construction 1 ,625
Total $47 ,870
Amount Eligible $ 685
Amount Ineligible 47 ,185
Local Share
Eligible Portion $ 305
Ineligible Portion 47 ,185
Total $47,490
*Costs are in September 1987 dollars (projected ENRCCI , 4665)
P afjn 9 <'f 11
i
WESTCHESTER COUNTY
• MAMARONECK SEWER DISTRICT
SEWER SYSTEM REHABILITATION
TOWN OF MAMARONECK
Project: I/I Correction
Program: Inflow Reduction
Technique: Direct Connection Removal - Project 5T
Description:
This project involves remediation of a common storm/sanitary manhole. The storm sewer
pipe will be encased and the wall extended to prevent the storm sewer pipe from
overflowing into the lower sanitary sewer. This manhole is located on private
property between Maple Hill Drive and Dante Street.
Estimated Project Cost*:
Bid Price $380
Contingency 120
Construction Engineering 45
Legal & Miscellaneous 25
Interest During Construction 20
Total $590
Amount Eligible $570
Amount Ineligible 20
Local Share
Eligible Portion $255
Ineligible Portion 20
Total $275
*Costs are in September 1987 dollars (projected ENRCCI , 4665)
Page 1(1 of 11
l0/Z?/1.
4
WESTCHESTER COUNTY
•
MAMARONECK SEWER DISTRICT
SEWER SYSTEM REHABILITATION
TOWN OF MAMARONECK
Project: Major Rehabilitation
Technique: Sewer Replacement - Project 1T-1
Description:
This major rehabilitation project involves the replacement of approximately 250 feet
of sanitary sewer with 30 inch diameter pipe. In addition, construction of a 3 I.1GD
pump station and installation of approximately 2,050 feet of 12 inch diameter force
main has been proposed. Also, it has been estimated that installation of 10 manholes
will be required. The anticipated project route extends from Baldwin Place to Laurel
Harmon Drive.
Estimated Project Cost*:
Bid Price $1 ,310,000
Contingency 327,800
Construction Engineering 144,150
Legal & Miscellaneous 81 ,900
S;r Interest During Construction 65,600
Total $2,249,450
Amount Eligible $1,863,850
Amount Ineligible 385,600
Local Share
Eligible Portion $ 279,575
Ineligible Portion 385,600
Total $ 665,175
*Costs are in September 1987 dollars (projected ENRCCI , 4665)
•
rail, 11 o1 11
•
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