25-51 RFQ - Design Services for Sewer PS 19 & 21 Replacement

Agency:	City of Mercer Island
State:	Washington
Type of Government:	State & Local
NAICS Category:	237110 - Water and Sewer Line and Related Structures Construction 541330 - Engineering Services
Posted Date:	Oct 27, 2025
Due Date:	Dec 11, 2025
Original Source:	Please Login to View Page
Contact information:	Please Login to View Page
Bid Documents:	Please Login to View Page

Attachment Preview

Request for Qualifications (RFQ) for

Design Services for Sewer PS 19 & 21 Replacement

RFQ No. 25-51

Released: October 27, 2025

Due: 2 pm (PST), December 11, 2025, to bids@mercerisland.gov

INTRODUCTION

The City of Mercer Island (City) is requesting Statements of Qualifications (SOQs) from qualified professional engineering

firms interested in providing design and support services for the Sewer Pump Station (PS) 19 & 21 Replacement project.

The awarded firm shall be licensed and lawfully engaged in providing engineering services in the State of Washington.

BACKGROUND

Mercer Island’s sewer system, constructed in the 1950s and 1960s, includes approximately 2,400 manholes, 105 miles of

pipe, and 18 pump stations (17 pump stations and 1 flush station). Most stations are near the shoreline, generally within

50 feet, and convey flow through the lake line to King County’s South Treatment Plant. The stations are primarily wet-

well/dry-well designs, with two currently submersible and two additional stations planned for conversion. Significant

upgrades have not occurred since their original construction except at Pump Station 4 (2010), Pump Station 14 (2014),

Pump Station 11 (currently being rebuilt by King County), Pump Station 20 (currently nearing 100% design), and all

stations recently received a major SCADA system upgrade.

In 2015, a condition assessment evaluated each pump station based on its consequence of failure. In January 2024, RH2

Engineering completed an assessment that prioritized improvements for the five stations found to be in the poorest

condition. In 2025, the City conducted wet-well inspections during cleaning activities to document structural

deterioration. Collectively, the 2015 and 2024 assessments and the 2025 inspection findings identified Pump Stations 19

and 21 as next in line for immediate rehabilitation or replacement.

SCOPE OF WORK

Project Description

The purpose of this project is to provide engineering support and design services for the rehabilitation and replacement

of Sewer Pump Stations 19 and 21. Both wet-well/dry-well stations, originally constructed in 1966, have reached the end

of their useful life. Work at each site will include removal and replacement of pumps, piping, mechanical systems, and

associated electrical and control equipment; repair, rehabilitation, or replacement of concrete vault structures; and

utility reconfiguration, modernization, and site improvements. While the design will be informed by existing

documentation and specifications from previous pump station projects, consultants shall also consider each site’s

unique characteristics and apply innovative design and construction solutions. The objective of the project is to extend

the service life of each station by approximately 50 years while minimizing impacts to nearby residents and the shoreline

environment.

See the following site attributes and design considerations:

RFQ No. 25-51 | PS 19 & 21 Replacement Design

RFQ Page 1 of 8

Shoreline Design

Considerations

Operational and

Infrastructure

Design

Considerations

Equipment Design

Considerations

Location Design

Considerations

Construction Design

Considerations

ALL SITES

• Existing structures are legally non-conforming

• New development (anything outside existing station footprint) is subject to:

o Hardscape coverage: 10% within 0–25 ft of OHWM; 30% within 25–50 ft

o Structure height: ≤30 in above existing or finished grade (whichever is lower)

within 0–25 ft of OHWM

o Design to comply where feasible to avoid the need for variances

• Create intermediate access structures between pump stations and influent lines for

inspection and cleaning of the Lakeline

• Modify piping/mechanical to facilitate future bypass operations

• Remove/abandon emergency overflow

• Install flow meter on discharge header

• Salvage and reuse recently upgraded SCADA equipment panels and components:

o PLC panel, Intrinsically Safe (IS) panel, Horn-Beacon panel, Go-No go panel;

modem and antenna

• Standardize Flygt N-Technology pumps

• Improve visual aesthetics and reduce impact on adjacent residents

• Implement odor control improvements

• Utilize native plantings to screen utility infrastructure and enhance site ecological

function

• The pump stations cannot be taken offline

• Any flow-impacting work requires a temporary sewer bypass.

• Project design shall include site specific bypass plans indicating all required

components, pump suction/discharge locations, piping configuration, flow information,

and property owner impacts/mitigation.

• All phasing and sequencing for shut-downs, cutovers, or bypass operations shall occur

during the design phase.

Location & capacity

Configuration

Site footprint and

structures

Access

Site Specific Design

Considerations

PS 19

• 7697 W Mercer Way; 0.2000 MGD at RFQ release

• Wet-well/dry-well; wet well west wall forms shoreline bulkhead

• City-owned right-of-way (~40×40 ft square along shoreline)

• 10-foot-wide vacated strip along the former 79th Street alignment connects the right-

of-way to W Mercer Way (impassible)

• 6’×36’ service dock (1966)

• SCADA antenna

• Land Access 1: W Shuck Park Dr turnaround; easement limited to private road; 4

vehicles;~700 ft walk; narrow, winding, vegetated; slippery; verbal right-of-entry

• Land Access 2: 7701 W Mercer driveway/steps; steep; easement in place; limited

parking; unusable when slick/icy.

• Boat: 36’ service dock; construction barge required for major work

• Adjacent to residences at 7677 & 7701 W Mercer

o Regular odor complaints

• May be room on-site for temporary bypass and staging of materials/equipment

• Potential for minor expansion/conversion to a submersible station, consistent with the

design approach used for Pump Station 20

• Improvements to Land Access 1 / alternatives

• Service dock rehabilitation

• Other improvements

o vegetation/tree removal, grading, water service, retaining wall, concrete

lattice pavers, equipment shelter, picnic/work table, native plantings

RFQ No. 25-51 | PS 19 & 21 Replacement Design

RFQ Page 2 of 8

Location & capacity

Configuration

Site footprint and

structures

Access

Site Specific Design

Considerations

PS 21

• 8000 Avalon Dr; 0.2046 MGD at RFQ release

• Wet-well/dry-well; projects from shoreline; N,E, and S walls form shoreline bulkhead

• Parcel 3124059059 (~28×28 ft)

• Original 6’x12’ service dock (1966) removed

o 36’x48’ footprint private dock and mooring pier added (1990 & 1993)

• SCADA antenna

• Land Access 1: Private driveway for 7694 E Mercer; easements in place; limited 2-hr

material/equipment use; narrow and exceptionally steep in last 80 feet; 2 vehicles;

heavy equipment ok; 40 ft walk across lawn

• Land Access 2: Private driveway for 8002 Avalon; easements in place; 10’ walkway

easement along northern property line to station; additional parking along Avalon Pl.

• Boat: City portion of station/dock only

• Location is backyard of 8002 Avalon Dr.

o Activities will greatly impact the residence and their use of the dock

o Regular odor complaints from station and HGMH

o Station expansion/reconfiguration requires close coordination and/or approval

from residents

• No room for temporary bypass or staging

• Maintain safe access to private dock during construction

• Maintain wet-well/dry-well configuration or convert to submersible (similar to PS 11 &

14)

• Improvements to Land Access 1 / alternatives

• Resurface deck

• Other improvements: water service installation

General Scope of Services

The scope of work at each site is expected to include, but not be limited to, the following tasks:

1. Conduct site visits and review relevant documents, studies, and other background information

a. This will involve entering confined spaces.

2. Perform a project area survey and create a project base map.

3. General at 3D model of existing facility

4. Complete project designs. Design work may proceed concurrently; however, assume that two separate

construction packages will be required.

a. 30, 60, 90% Design Construction Package (Plans, Specs, Estimate)

b. Long Lead Item Procurement Package

c. 100% Design (Bid-Ready) and Conformed Construction Package.

d. The following sheets are anticipated:

i. Cover

ii. General and Special Notes

iii. Existing and Proposed Site Plans

iv. TESC, BMP, and Tree Protection Plans

v. Civil/Grading

vi. Bypass and/or Phasing/Sequencing Details

vii. Demolition

viii. Mechanical

ix. Structural

x. Electrical

xi. Control

xii. Traffic Control/Barge

xiii. Restoration & Landscaping

RFQ No. 25-51 | PS 19 & 21 Replacement Design

RFQ Page 3 of 8

xiv. Standard Details

5. Develop an updated control strategy document

a. Detail the station’s operational logic, control sequences, and alarm functions based on the final design

6. Perform electrical power study

a. Evaluate the existing and proposed electrical systems for each station to ensure safe and reliable

operation. The study shall include, at a minimum, load analysis, short-circuit and protective device

coordination, and arc flash hazard assessment.

7. Provide permitting support during the design process.

a. City Responsibility: The City will serve as the lead agency, responsible for preparing, packaging, and

submitting all permit applications:

i. Mercer Island Community Planning & Development

1. Pre-Application Meeting

2. SEPA Review

3. Shoreline Development Application/Shoreline Exemption

a. Project Narrative

b. Tree Inventory/Arborist Report

4. Shoreline Variance Request

a. Criteria compliance narrative

ii. Joint Aquatic Resources Permit Application (JARPA)

1. WA Department of Fish & Wildlife: Hydraulic Project Approval (HPA)

2. WA Department of Ecology: Section 401 Water Quality Certification

3. WA Department of Natural Resources: Aquatic Resources Use Authorization

4. Department of the Army permits:

a. Section 404 (discharges into waters of the US):

b. Section 10 (work in navigable waters):

b. Consultant Responsibility: The consultant will be responsible for preparing the necessary supporting

documents for inclusion in the City’s submittals which may include, but shall not be limited to the

following:

i. Mercer Island Community Planning & Development

1. Mitigation sequencing pursuant to MICC 19.07.100

2. No net loss report/plan

3. Setback Hardscape Calculations/Exhibit

4. Setback Structure Height Cross Sectional View

5. Geotechnical report, if existing reports on record are not sufficient

6. TESC Plan and project specific BMPs

7. Wetland Identification – PS 19 is located in moderate probability area per City GIS. If

identified perform:

a. Wetland Rating and Delineation Study, if wetland is identified

b. Buffer averaging or reduction calculations/technical memo, if required

c. Wetland or wetland buffer mitigation plan, if required

8. Critical Area Study meeting the requirements of MICC 19.07.110

a. To be determined pending final design, wetland identification, or exemption

disapproval.

ii. JARPA

1. Site maps required per section IV.G of the JARPA application instructions

a. Vicinity Map

b. Plan View (birds eye view)

c. Cross-sectional view

2. Wetland Mitigation Table, if a wetland is found to be present, which includes:

a. Area (sq. ft.), Cowardin/wetlands Classification, ecology rating, impacts (sq. ft.),

compensation - reestablishment or creation (areas and ratios), rehabilitation -

areas and ratios, enhancement - areas and ratios.

8. Provide Public Outreach Support

RFQ No. 25-51 | PS 19 & 21 Replacement Design

RFQ Page 4 of 8

a. Attendance at meetings with residents

b. Respond to questions from the public

c. Provide site plans, exhibits, and project renderings for public distribution.

d. Assumptions:

i. The City will be responsible for coordinating and leading all city council, community, and/or

resident meetings.

ii. The City will create and maintain the project webpage

9. Provide engineering support during the bidding process – pre-bid meeting attendance, respond to bidder

questions, and update the plans and technical specifications, as required.

a. The City will be responsible for advertising, fielding all questions, and issuing addenda.

10. Provide engineering support during construction – including attendance at the pre-construction meeting,

review of RFIs and submittals, and general construction-phase support.

a. The City will be responsible for daily field inspections and coordination with the Contractor.

b. The Consultant shall provide up to 16 hours per month of on-call support during the construction phase.

This support may include special field inspections and direct communication with the Contractor and/or

subcontractors to observe work or resolve construction-related issues.

11. Prepare and deliver construction as-built record drawings.

The City expects the project manager from the selected firm to work in close consultation with the City’s project

manager throughout the project duration and ensure projects remain on schedule and within budget.

MANDATORY SITE VISIT

Interested engineering firms must schedule and attend a site visit prior to the questions deadline of Wednesday,

December 3, 2025, at 12:00 PM (PST) to be eligible for award. Visits can be scheduled via email or phone with

Christopher Marks, Utilities Engineer, at chris.marks@mercerisland.gov or 206-677-1027. Each visit will include tours of

both pump station sites during normal business hours and may be consolidated to accommodate multiple firms. Entry

into the stations is optional; firms electing to enter must provide and follow their own confined space entry protocol,

including required personnel and equipment. Questions raised during site visits will be documented and posted along

with other questions received during the open question period.

STATEMENT OF QUALIFICATIONS

Interested engineering firms are invited to submit a Statement of Qualifications (SOQ) for this work. Page counts listed

below are approximate and may vary, provided the total submittal does not exceed the maximum page limit. The SOQ

must include the following information:

Letter of Intent (1 page):

Provide a concise cover letter summarizing your firm’s background, available resources, and commitment to

delivering the services described in this RFQ. The letter should express your firm’s specific interest in this project and

in working with the City of Mercer Island, highlighting any unique qualifications or value your team brings to this

effort.

Include the address, telephone number, and primary contact for the office located nearest to Mercer Island,

Washington, as well as the office from which the project will be managed. The letter must be signed by an individual

authorized to commit the firm to the terms and conditions of this proposal.

Project Understanding, Approach, and Schedule (8 pages):

Describe your team’s overall approach to meeting the City’s project objectives and how your team will work with City

staff throughout project development and delivery. Review all materials provided with this RFQ, including site photos,

property documents, as-builts, and existing assessments. Firms are required to schedule and attend a mandatory site

visit.

Identify any additional site investigations or data collection needed to begin design.

RFQ No. 25-51 | PS 19 & 21 Replacement Design

RFQ Page 5 of 8

This page summarizes the opportunity, including an overview and a preview of the attached documents.

Title	Bid/RFP Closing Date	Status	Files	View
25-51 RFQ - Design Services for Sewer PS 19 & 21 Replacement	12/11/2025 - 2:00pm	Open - accepting bids and proposals		25-51 RFQ 25-51 Exhibit 1 25-51 Exhibit 2 25-51 Exhibit 3 25-51 Exhibit 4 25-51 Exhibit 5 25-51 Exhibit 6 25-51 Exhibit 7	View Details

25-51 RFQ - Design Services for Sewer PS 19 & 21 Replacement

Attachment Preview

Sign-up for a Free Trial, Government Bid Alerts

See Also