Document 1564649

DEPARTMENT OF ENVIRONMENTAL QUALITY
City of Clio, Collection System Improvement Project
State Revolving Fund/Strategic Water Quality Initiatives Fund Grant
Environmental Assessment
December 2015
I.
II.
PROJECT IDENTIFICATION
Applicant Name:
City of Clio
Authorized Representative:
Mr. Eric Wiederhold, City Administrator
Applicant’s Address:
505 West Vienna Street
Clio, Michigan 48420
Project Number:
9185-01
PROJECT SUMMARY
The city of Clio obtained a State Revolving Fund/Strategic Water Quality Initiatives Fund (S2) grant
for $153,283 in January 2012 to pay for planning costs for sewer system improvements in
response to basement backups during storm events. With the S2 funding, the city of Clio
conducted a sewer investigation, and prepared and submitted a State Revolving Fund (SRF)
project plan. The submittal of an SRF project plan is a requirement of obtaining the S2 grant and
is the basis for the information in this environmental assessment. It was known prior to the sewer
investigation that the sewer system was at least 50 years old and had excessive infiltration and
inflow (I/I), or clear water, during storm events. Infiltration is groundwater that enters the
collection system from the soil through cracks, defects, and/or breaks in sewer pipes or
manholes. Inflow is water that enters the system more directly through connected
foundation/footing drains. Therefore, the purpose of the sewer study was to more precisely and
accurately quantify the volumes and locations of the excess clear water. This was accomplished
by isolating and examining 12 sections of the sewer system by the placement of meters. It was
determined that 77 percent of the wastewater flow is due to I/I and that four of the districts,
Districts 3, 6B, 7, and 10B, are responsible for 70 percent of the overall I/I flow (see Figure 1 for a
map of the district locations).
Clio is proposing to reduce the number of basement backups for storm events up to the 25-year,
24-hour design storm event with a sewer upgrade project. The proposed project consists of
replacing approximately 1,200 feet of structurally deficient sewer in District 3 and 6B, replacing
approximately 2,900 feet of undersized sewer in District 3, 7, and 10B, and installing a new
200-foot-long sewer to connect to the Genesee County Interceptor in District 6B (see Figure 2 for
project locations). Construction is targeted to occur from May 2016 to September 2016. The
project cost is estimated to be approximately $1,016,409 and is anticipated to be funded by a
combined grant and loan from the United States Department of Agriculture’s Rural Development
(USDA-RD) program. For a 20-year loan through the SRF Program at 2.5 percent interest, the
impact to the monthly user charge would be expected to increase approximately $42 per year per
residential equivalency unit (REU), or $3.50 per month; however, rates resulting from the
USDA-RD loan/grant will differ.
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II.
PROJECT BACKGROUND
A. Existing System Description
The Clio collection system serves residents and businesses located within the city limits,
which has an area of 1.1 square miles. The 2015 population is estimated to be 2,650, and
there are 983 residential and commercial customers in the city. The collection system
consists of 11.5 miles of gravity sewer, ranging in diameter from 8 inches to 18 inches, and
one lift station, constructed in 1974. The collection system empties into an interceptor owned
and operated by Genesee County Water and Wastewater Services (GCWWS). The
GCWWS Interceptor is located on the east side of the city near Pine Creek. The city
discharged 384.24 million gallons of wastewater into the GCWWS Interceptor in 2010.
Recent flows have been similar. The city does not have a restricted limit with GCWWS and
is charged $8.12 per 1,000 gallons of wastewater discharged into the GCWWS Interceptor.
The collection system is a separated system that operates by gravity. The oldest sewers
are approximately 50 years old or older. The collection system was evaluated in a
February 2013 report, the “Summary Report Inflow and Infiltration Analysis and Sewer
System Evaluation Survey.” The Sewer System Evaluation Survey (SSES) report also
identified areas in the collection system where the existing pipes had insufficient capacities.
B. Need for the Project
The collection system is known to have excessive I/I. For example, in 2010, metered flows
entering the GCWWS averaged 637 gallons per capita day (gpcd) for flows during high
groundwater (March, April, May, September, October, and November), which far exceeds the
state standard of 275 gpcd.
The project need is to replace pipes that require immediate attention due to concerns of the
structural integrity of the pipes and to reduce or eliminate basement backups. The pipes that
need immediate replacement were determined to be structurally deficient by video inspection
and are located on Bluff Street, M-57, and in a commercial area bounded by Pine Run Creek,
M-57, East Young Street, and Railway Street.
After it was determined that Districts 3, 6B, 7, and 10B contribute more than 70 percent of the
I/I, further testing was focused on those four districts to determine why and how the I/I was
entering the sewers. The most common factor for I/I was found to be from many small
sources including sewer joints, service lead taps, small cracks, and a high water table. Based
on the video inspection, it was found that approximately 11 percent of the sewer system in the
four districts was in poor structural condition and another 49 percent was in need of
maintenance. Smoke testing showed that there were negligible storm sewer
cross-connections to the sanitary sewer system, which can often be a common source of
inflow. The source of I/I was determined to be different in District 7 because many of the
sewer pipes in this district and two districts that flow into District 7 were replaced recently.
Therefore, the excessive I/I is likely the result of illicit footing drain connections from
residences. Improper manhole covers and manhole rings are often a source of I/I in wet
systems; however, in this case, manholes were not shown to be a significant source of I/I.
In addition to sewers with immediate structural integrity needs and sewers with excessive I/I,
there is a need to upgrade sewers that are undersized. Undersized sewers, especially when
there is excessive I/I, can result in surcharging and basement backups. There were
36 recorded basement backups from 2003 to 2013, 35 of which occurred due to an event
equal or less than a 25-year, 24-hour storm event. Simulation testing was performed using
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Environmental Protection Program software and showed that 11 sections of pipe were
surcharging under the design storm event. These 11 sections totaled 6,180 feet of sanitary
sewer.
C. Alternatives Considered
Taking no action and examining a regional alternative are a required component of an SRF
project plan. For this project, taking no action is not feasible because the problems will only
get worse with the addition of time, resulting in more pollution events. Clio already belongs to
the closest regional system, so regionalization is not a logical alternative. Even if a second
regional system existed nearby, the city’s operational problems are due to the condition of the
city’s sewer pipes, which a regionalization alternative would not address; therefore,
regionalization is not a feasible alternative for addressing the project need.
The alternatives for addressing the project need consist of first determining whether
constructing additional capacity is more cost-effective than removing the excessive I/I.
Because GCWWS does not have a discharge limit and because the operational problems are
not originating from the connection to the county interceptor, additional capacity at the end
point of the city collection system is not a factor. However, an inline retention basin is
plausible and is, therefore, a component of the transportation and treatment calculation that
was examined. A retention basin is a wastewater facility constructed to retain and equalize
the flows between the extremes of the average daily flow. It holds the first flush of peak wet
weather flows until the downstream portion of the system has the capacity to receive the
basin’s contents. The capital cost of constructing a basin for each of the four districts is
approximately $10,000,000. This becomes prohibitively expensive as an alternative and
needs no further analysis. Because retention is not an alternative, the feasible alternatives
are focused on how to cost-effectively remove the I/I and reduce capacity issues in ways
other than a retention basin.
Three principal alternatives were examined for removing the I/I from District 3, 6B, 7, and 10B
with the elements of repairing the structurally deficient pipe, upsizing some pipes to increase
capacity, and lining sections of pipe to eliminate I/I, common to all three options. Additional
considerations are described below:
•
Footing drain disconnections, gutter, and downspout installation, service lateral
repairs, and disconnection of footing drains from the service lateral. - Based on a
study of 18 homes, it was assumed that 10 percent of the homes have footing drain
connections. Gutters and downspouts would be added to buildings without them and
those with roof drains connected to the sewer system would be redirected to the storm
drains. Service laterals would be rehabilitated or replaced if needed. Missing or
damaged cleanout caps would be repaired.
•
A new interceptor connection to GCWWS - An additional connection to the county
interceptor would be placed at the east end of Johnson Street to reduce flows by
redirecting some flows into the county interceptor before they cause capacity issues.
Upon further review of the sewer televising data, it was determined that the cost to re-line
sewer sections with excessive I/I would be greater than the cost to transport flow to the
county. Therefore, the sewer lining work was removed from the scope of the project.
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IV. DESCRIPTION OF THE PROPOSED PROJECT
It is anticipated that addressing all of the needs in the project plan will cost approximately
$1,016,409. The proposed project consists of replacing approximately 1,200 feet of structurally
deficient sewer in District 3 and 6B, replacing approximately 2,900 feet of undersized sewer in
District 3, 7, and 10B, and installing a new 200-foot-long sewer to connect to the GCWWS
interceptor in District 6B. (See Figure 2). The system improvements are designed to ensure that
this population’s wastewater reaches the GCWWS interceptor at all times and without
surcharging and basement backups for all conditions up to and including a 25-year, 24-hour
storm event.
Once I/I has been removed from District 3, 6B, 7, and 10B, and the system is monitored, the city
will be able to determine if any additional problems need to be addressed. Construction is
targeted to occur from May 2016 to September 2016, contingent on receiving obligation through
the USDA.
V.
IMPACTS OF PROPOSED LOCAL RELIEF PROJECT
A. Direct Impacts
Construction will primarily take place in existing sewers and will involve open trench
construction. The proposed construction will cause temporary disruption to neighborhood
residents through dust and noise, and potential alternate routing of traffic through
neighborhoods. Underground utilities may be interrupted for short periods of time.
The area is predominately residential, and there are no unique natural settings, sensitive
ecosystems, or endangered species.
A State Historic Preservation Officer has reviewed the proposed project for impacts on
historical and archeological resources. It has been determined that there will be no impact on
historical or archeological resources from the proposed project. The Native-American Tribal
Historic Preservation Office contact for Genesee County was given the opportunity to
comment on the project plan and will receive a copy of this document. The construction area
of influence is mostly confined to residential streets where no suitable wildlife habitat is
present for state and federal endangered, threatened, or special concern species. As such, it
was determined that the project will have “no effect” on state and federally listed species.
Examination of the Floodplain Insurance Rate Map indicated that the proposed new county
interceptor connection is located in the 100-year floodplain of Pine Run Creek. However,
proposed construction is at present grade levels and will not impact existing trees; therefore, it
is not considered to have a significant impact. A Michigan Department of Environmental
Quality (DEQ)/United States Army Corp of Engineers “Joint Permit Application” will be filed for
all work proposed within the Pine Creek floodplain. This permit package covers permit
requirements pursuant to state and federal rules and regulations for construction activities in
areas referred to as the land/water interface.
There is one location where Pine Creek will be crossed: between the west end of Jefferson
and the county interceptor. This work will be completed by jacking and boring under the
stream bed. This technique involves digging a bore pit and receiving pit at pre-determined
depths. A boring machine placed in the initial bore pit pushes an auger and the pipe,
generally called a casing, through the ground simultaneously while the machine turns a
cutting head through the ground. The auger carries the debris back to the initial pit for
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removal. This technique is used to minimize surface settling or heaving. The equipment can
be loud and cause vibrations; however, this is standard for this method of construction.
It was anticipated that a second crossing would be necessary at the Johnson Street
interceptor connection; however, additional survey work in the area found the sewer
interceptor to be on the west side of the creek, and no crossing would be required.
Mitigation of short-term construction impacts to the area residents will entail standard
construction procedures for traffic control and rerouting, safety issues, dust control, cleanup of
area, and complete restoration of lawns, curbs, and streets. Soil erosion and sedimentation
controls, and restoration requirements will be included in the contract specifications, which will
ensure compliance.
B. Indirect Impacts
Sanitary sewers are available throughout the city, and capacity is not expected to increase
through sewer expansion. The population within the project area is not anticipated to
increase significantly over the 20-year planning period. The proposed sanitary improvements
are expected to accommodate any anticipated increase.
As a result of this proposed project, it is expected that the removal of excess I/I will benefit the
GCWWS treatment process, thereby improving the quality of the regions’ water resources as
a long-term, indirect benefit.
C. Funding Information
In December 2010, the DEQ passed legislation establishing the S2 grant program with the
intention of spurring municipalities to increase wastewater infrastructure construction. In
response to the creation of the S2 grant program, the city of Clio applied for an S2 grant,
No. 9185-01, in the amount of $153,283 for the purpose of studying its sewer collection
system in order to eliminate basement backups in residential basements. The project cost is
estimated to be approximately $1,016,409, funded by a loan/grant from the USDA-RD.
VI. PUBLIC PARTICIPATION
A public hearing on the 2013 Project Plan was held on March 18, 2013, at the city of Clio’s office.
A presentation outlining the alternatives and detailing the selected alternative was presented at
the hearing. On April 15, 2013, after the project plan presentation and question-and-answer
period was completed, the Clio City Commission passed a resolution adopting the recommended
alternative and authorizing the project to proceed. No written comments were received from the
public during the 30-day comment period. Comments and questions were received from the city
commission and two citizens. A second public hearing was held on November 4, 2013, also at
the city of Clio’s office, as the first hearing had not been advertised for a full 30 days. Again, after
the project plan presentation and question-and-answer period was completed, the Clio City
Commission passed a resolution adopting the recommended alternative and authorizing the
project to proceed.
VII. REASONS FOR A FINDING OF NO SIGNIFICANT IMPACT
The project detailed in this environmental assessment involves the reduction of I/I by the
replacement of sewers that lack structural integrity or are under-sized and the addition of another
connection to the county interceptor. The short-term impacts of this construction to area
residents will involve inconveniences such as noise, dust, erosion, and traffic congestion.
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Mitigative measures for these short-term impacts include adequately marked construction areas,
appropriate traffic control and rerouting through neighborhood areas, and restoration of disturbed
areas, such as lawns, sidewalks, and road pavements. Any unexpected disruption of utility
services will be restored in a timely manner. Adherence to contract specifications for mitigative
measures and sound construction practices will minimize the construction impacts, and
communication with residents directly impacted by the construction will be maintained.
It is not expected that the proposed construction will impact any environmentally sensitive areas,
wildlife habitat, wetlands, or cultural resources.
It is not anticipated that there will be any long-term adverse impacts from the proposed
construction project. The long-term benefits of removing clear water from the sewer system, and
providing sufficient capacity in the sewer system to eliminate the potential for basement flooding
and system bypasses to the area waterways during storm events up to the 25-year, 24-hour
intensity level, can be accomplished with non-significant and temporary disruptions.
Any questions or concerns about this Environmental Assessment can be directed to:
Ms. Sonya T. Butler, Chief
Revolving Loan Section
Office of Drinking Water and Municipal Assistance
Michigan Department of Environmental Quality
P.O. Box 30241
Lansing, Michigan 48909-7741
Telephone: 517-284-5433
E-mail: [email protected]
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