Design-Build Procurement Approaches - Design-Build for Water and Wastewater Projects - page 81

Project: Blendville Water Treatment Plant Improvements and Expansion
Owner: Missouri American Water Company
Design-Build (DB) Entity: Reynolds Inc. (contractor); Gannett Fleming
(engineer)
Completion Date: December 2008
Description of Project
The Blendville Water Treatment Plant (WTP) in Joplin, Mo., began service in the
1890s. Prior to this project, the WTP was last upgraded in the 1950s. After Joplin
experienced high water usage in 2006, Missouri American Water Company (Mis-
souri American) predicted that average daily water use would increase more than 2.3
percent annually, with maximum daily demands exceeding the 16-mgd (60-ML/d)
capacity of the WTP. The Blendville WTP required extra capacity and process reno-
vations to safely and reliably meet the demand of more than 25,000 customers in and
around Joplin.
Missouri American improved and expanded the Blendville WTP from 16 mgd
(60 ML/d) to 21.5 mgd (81 ML/d). Plant upgrades included a new chemical build-
ing; a new administration building; a new filtered-water transfer pumping station;
ultraviolet (UV) disinfection; additional clearwell capacity; a process wastewater
equalization basin; a wastewater pump station; an off-site wastewater lagoon; new
primary electrical service and distribution; and supervisory control and data acqui-
sition (SCADA) system enhancements. The WTP expansion features flocculation,
plate settlers, and filters. Improvements to the existing WTP included filter aid poly-
mer feed and de-icing systems for purification units, filter valve rehabilitation, and
high-service pump replacements. In addition to plate settlers and UV, innovative
features included on-site hypochlorite generation and liquid lime. The hypochlorite
system eliminated gas chlorine storage and delivery, and the bulk liquid lime storage
and feed system alleviated maintenance hassles associated with dry lime.
This project's biggest challenge, and one of Missouri American's biggest con-
cerns, was that the existing plant had to stay in operation throughout construction.
The design-builder and Missouri American collaborated to develop a construction
sequence that enabled the project to be completed in the allotted time while mini-
mizing disruptions to plant operations.
Several complete plant shutdowns were required to replace existing filter valves.
WTP operators were very concerned about problems occurring during the shut-
down that may have prevented the plant from coming back online. Issues such as
having all of the correct parts available, or damaging a part during installation, could
have prevented pipe reconnections in the allotted time and seriously disrupted cus-
tomer service.
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