HomeMy WebLinkAboutMurray Smith Assoc Sewer Modeling for Sharma DevelopmentM
November 9, 2015
PUBLIC WORKS DEPARTMENT
PO Box 293 (525 North 3` Avenue) Pasco, R
ORIGINAL
545-3444 / FAX (509) 543-5728
ton 99301 / www.pasco-wa.gov
LETTER OF AGREEMENT
Murray, Smith & Associates, Inc.
Attn: Joe Foote, PE
421 W. Riverside Ave., Suite 762
Spokane, WA 99201
RE: Letter Agreement— Sewer Modeling for Sharma Property Development
Dear Mr. Foote:
The City desires to engage the professional services and assistance of Murray, Smith &
Associates, Inc. to provide professional engineering services to assist in evaluating the
capacity of specific sewer lines using the City's sewage collection system computer model
with respect to the Sharma Property Development
The scope of services is outlined on Exhibit A with an estimated cost of not to exceed $3,000
and a completion date of November 30, 2015.
The City of Pasco and Murray, Smith & Associates, Inc. agree to the terms of this Letter
Agreement by signing below:
Ahmad Qayoumi, P.E. Date J4 Foote, P.E. Date
Public Works Director Murray, Smith & Associates, Inc.
AQ/pma
d GCo 5
SCOPE OF SERVICES
CITY OF PASCO, WASHINGTON
SHARMA PROPERTY - SEWER MODELING
This scope of work is for professional engineering services provided by Murray, Smith &
Associates, Inc. (MSA) for the City of Pasco, Washington (City). Services associated with
this scope of work involve the use of the City's sewage collection system computer model to
assist in evaluating the capacity of specific sewer lines.
Background
MSA completed a General Sewer Plan Update for the City in 2014. As part of that project
an updated sewer hydraulic model was constructed, calibrated and used to identify available
capacity in the system. The model was developed in InfoSWMM and simulations were
developed for existing and future dry and wet weather conditions. The model can now be
used to assess the capacity of specific pipelines in the system as new development or
additional flows are proposed.
SCOPE OF SERVICES
Task I — System Capacity Analysis
The City is evaluating the capacity of the sanitary sewer system to serve a new development
(Sharma Property) which includes 17 acres (56 units) on the corner of Broadmoor and Dent
Road. The new development would connect into the existing sanitary sewer piping at the
intersection of Nottingham Drive and Norfolk Drive.
MSA will develop sanitary sewer loading and flow rates for the 56 units based on unit
loading assumptions from the General Sewer Plan. The existing and future system models
will be updated to include the refined flow rates for dry and wet weather conditions. Model
scenarios will be created and simulated for one existing condition and one future condition.
The analysis will identify and document any potential sewer capacity deficiencies associated
with the new development. System deficiencies will be based on City design criteria related
to maximum water depth to pipeline diameter ratios during peak dry weather and maximum
surcharging allowances during peak wet weather. Any locations where pipelines or
manholes exceed the accepted City design criteria will be identified. Additionally, MSA will
determine the maximum number of units that can be connected to the existing system, if the
zoning is changed to allow for an increased density.
Assumptions: MSA will utilize the existing hydraulic model without modification except for
the flow/loading update for the Sharma Property. MSA will utilize the design standards
developed for the General Sewer Plan Update in the analysis. No on-site meetings or field
work are included in this scope of work. Existing and future (20 year) conditions will be
City of Pasco, WA MURRAY, SMITH & ASSOCIATES, INC. On- Call Sewer Modeling
September 2015 Engineers/Planners _ I of 2___
Exhibit A
evaluated. The scope and budget are limited to one service alternative for connection at
Nottingham Drive.
Deliverables: A final technical memorandum summarizing the analysis will be provided in
electronic format.
Fee Estimate
The total budget for this work is estimated at $3,000. All proposed work will be completed
on a time and materials basis not to exceed the total amount identified without prior written
authorization from the City.
Time of Performance
Completion of the work is dependent on a Notice to Proceed from the City and will be
accomplished within four weeks of that date.
City of Pasco, WA MURRAY, SMITH & ASSOCIATES, INC. On- Call Sewer Modeling
September 2015 Engineers/Planners 2 of 2