In 2007, Kruger, Inc., Black & Veatch, and Tetra Tech FHC partnered to design the operations and component systems for a water treatment plant in Bartlesville, USA. Various environmental and technological circumstances lead the plant into numerous problems.
After things started to go wrong, the three companies publicly addressed the issues raised at a news conference in 2007. All representatives present made assurances that they were working closely with city officials to find solutions to the operational challenges faced by the plant, and which had necessitated water conservation by the locals.
Jon D. Nelson, vice president of Tetra Tech FHC of Tulsa, described the plant as “state of the art” and said each plant has its own personality. He added that while officials have been encouraged by recent results, they were not quite ready to lift conservation efforts being made by the Bartlesville people.
The plant is rated at more than 27 million gallons per day (MGD) at full capacity, however the city water utilities director Mike Hall said that due to public conservation efforts, demand at one point plummeted to under 10 MGD.
Where the problems began
Officials suggested exceptionally heavy rain and flooding during June as the start of the plant’s problems, claiming that these anomalous weather patterns significantly changed the water quality in nearby Hudson Lake, affecting both levels of alkalinity and turbidity and therefore affecting the plant’s capability to produce a sufficient water to meet demand.
As a result of the heavy rainfall Total Organic Carbon (TOC) levels more than doubled from historical averages of 5 mg/L to 10 to 12 mg/L TOC. In addition, pH and alkalinity approached historical low values. Solutions needed to be found and in the meantime, officials were asking water customers to continue volunteer conservation efforts.
The plant used a sand filtration system to filter out sediment, or clarify, drinking water.
Black & Veatch’s role within the partnership was to contribute and manage the engineering design for the plant. Mike Orth, associate vice president, Black & Veatch of Kansas City, Missouri, defended the plant saying “we believe we have a sound process,” pointing out that the treatment process selected for the Bartlesville plant was a proven process used at over 100 installations throughout North America.
The plant used a sand filtration system to filter out sediment, or clarify, drinking water. This filtration system is a conventional dual media system consisting of sand and anthracite which effectively strains the material out of the process water that failed to settle-out during the sedimentation process.
Changing the coagulant
Mike Orth also addressed the various problems of the plant’s operation as a result of both the sand pumps and sand filters being used, saying “We’ve had some instances where these sand pumps were shutting down,” however, he added that recent data had indicated an improvement in the process.
The primary coagulant was a blended coagulant/polymer product that performed adequate under normal water quality conditions. However, the increased organics, along with a doubling of plant demands due to extreme temperatures, required the coagulant dosage to more than double, which significantly increased the polymer being fed to the process. The polymer created a blanket of material on top of the filters which increased the headloss across the filters, restricting plant production rates.
In order to improve this process, alternative coagulants were tested and a product was selected that didn’t contain a polymer. This allowed the plant operations staff to fine tune the coagulant and the existing polymer systems independently to optimise the treatment process.
According to a joint statement issued by the companies, the city recently began using aluminium chlorohydrate (ACH) as its new primary coagulant. The chemical is designed for more effective raw water treatment, with pre-testing of the chemical in laboratory and full-scale operations showing promising results.
Other issues that also contributed to the plant’s problems were related to water quality – the plant being briefly out of compliance with federal drinking water requirements, necessitating a change in treatment chemistry. This change was to add alkalinity to the water through the addition of sodium hydroxide to provide more stability of pH.
The statement went on to mention that: “It is important to note that there are numerous types of chemicals used at different water treatment plants based on the geographic location of the plant and the various types of water supply available – each plant requires specific and unique types of chemicals for its operations.” •
Other forthcoming Black&Veatch projects
Client: Detroit Water and Sewerage Dept
Project: Process Improvement
Location: Detroit, Michigan
The existing performance management system utilised by the Detroit Water and Sewerage Department (DWSD), which serves approximately 4 million customers in the Detroit area, suffered from common problems: complex systems, too much data and not enough information. The complex arrays of data made it difficult to identify causes of missed targets, ranging from maintenance orders to customer requests. Although the system incorporated multiple data points, it neither provided access to truly actionable information, nor did it provide the ability to analyse performance.
To address these issues, DWSD turned to Enterprise Management Solutions (EMS), the management consulting division of Black & Veatch, to create a new performance management system to help improve service to its growing base of customers. The goals of the new system were to improve organizational performance and provide the mayor’s office with a more robust and understandable system for reporting performance.
The solution was the creation of a new Performance and Dashboard System. The team evaluated more than 800 operational metrics to identify and create Detroit’s key performance indicators.
Key internal stakeholders were interviewed to gain an understanding of current performance metrics. Key metrics being provided for the mayor’s office also were reviewed to determine more effective ways to communicate the results externally. This, plus the EMS team’s knowledge of industry benchmarks, best practices and leading-edge techniques being employed at other municipalities drove the initial project design.
The resulting solution is a visual management tool that was installed on 70 stakeholders’ computers across the operation. The tool features a hierarchal view of the key performance indicators with traffic light displays that show green, yellow or red based on performance against the various indicators.
The system delivers a number of important new benefits for DWSD. The Performance and Dashboard System gives DWSD managers the information and detail they need to gauge how their departments or divisions are performing from month to month. It provides a much greater degree of accountability than the previous system. The new system generates a user-friendly, Web-based briefing book on the mayor’s computer that illustrates the “scorecard” on DSWD’s performance every month, including trends and commentary explaining each metric.
Client: City of Phoenix, Arizona
Project: Lake Pleasant Water Treatment Plant
Location: Phoenix, Arizona
Arizona’s vast desert landscape draws thousands of new residents every year, and proper planning for this growth has earned the city of Phoenix accolades as the best-managed city in the United States. Another remarkable achievement is at hand with the commissioning of the city’s new water treatment plant at Lake Pleasant – the largest design-build-operate project in North America. Phase I of this four-phased project provides a quality, reliable drinking water supply that meets existing and foreseeable future regulations and facilitates regional growth.
Black & Veatch is part of the joint-venture design-build team with McCarthy Building Companies, Inc., and American Water Services working with the city of Phoenix on the $336 million design-build-operate contract. The project stands out not only for its scope, but because the design-build-operate team has maintained the project schedule and a fixed budget despite facing significant challenges, including escalating materials costs and labor shortages. Change orders totaled less than 1 percent — an accomplishment virtually unheard of in a three-year construction schedule.
Construction of Phase I of the Lake Pleasant Water Treatment Plant began in the summer of 2004 and was completed early in 2007. This phase will deliver 80 million gallons (302.8 million liters) per day of capacity. Encompassing 225 acres (27.753 hectares), the project employs a series of processes to treat water from the Waddell Canal. Raw water is pumped through a 90-inch (228.60 centimeters) diameter pipeline approximately 12,000 feet (3,657.60 meters) in length to an innovative, state-of-the-art process system that features high rate sedimentation ballasted flocculation, ozonation, post-filtration granular activated carbon contactors and ultra-violet disinfection. Chemical dosing and solids processing facilities also are included. Treated water will be stored in a 40-million-gallon (151.4 million liters), partly buried, finished-water storage reservoir and transferred to the city’s distribution system by an on-site pump station.
The desert location of the Lake Pleasant Water Treatment Plant demanded an innovative, yet environmentally sensitive, approach to water treatment. Extensive use of indigenous materials links the natural and human environments; plant life and other native flora were preserved during construction in an onsite, five-acre nursery.
Contact:
George Minter
Email: minterga@bv.com
www.blackandveatch.com