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Brookfield Uses Innovative Treatment Technology to Meet Radionuclide Standards
City is First to Utilize New Approach in Wisconsin

Wisconsin Water Association Newsletter, Spring 2008
By Tom Grisa, PE, Public Works Director, City of Brookfield and Pat Planton, PE, SEH

Award-winning treatment/facility adjacent to
Utility well building,

In accordance with the Wisconsin Administrative Code Chapter NR 809.50 (2), the City of Brookfield Water Utility was required to bring its water system into compliance with the radionuclide standards set by the United States Environmental Protection Agency (USEPA). The City of Brookfield investigated many approaches to achieve compliance with these standards for its Brookfield Square well site before settling on the radium removal system provided by Water Remediation Technology. The system has been operating for about a year and has met radium compliance standards without fail.

Background
The 1986 Amendments to the Safe Drinking Water Act initiated discussions for the establishment of standards concerning safe levels of radionuclides in drinking water. Fourteen years later, in December of 2000, the USEPA finalized the much debated maximum contaminant levels (MCLs) for naturally occurring radionuclide substances in drinking water. The radium standard as finalized by USEPA is 5 picocuries per liter (5 pCilL) for the combined isotopes of Radium 226 and Radium 228. The gross alpha radiation standard is 15 pCiIL for contributions from radionuclide isotopes (excluding gross alpha radiation from uranium and radon).

In March 2002, water samples were collected from entry points throughout the City of Brookfield water system. The City operates 22 wells, the second highest number of groundwater wells for any water utility in Wisconsin, serving roughly 70 percent of the properties in a city of 40,000 residents. These samples were tested by the Wisconsin State Laboratory of Hygiene for gross alpha, gross beta, Radium 226, Radium 228, and uranium. Results of these tests 'became available from the State Lab in late fall of 2002. Samples from the Brookfield Square wells 1 and 2 exceeded the radionuclide standards. The radium reading was 6.4 pCiIL while gross alpha was recorded at 24 pCiIL.

Alternatives investigated
Even before radionuclide standards were announced by USEPA, the City had started working on its plan for addressing the issue. During the time MCLs were being debated, the City of Brookfield Water Utility commissioned an engineering study to evaluate its present water system and determine the best ways of meeting the water demands of the City. This study included evaluation of water supply sources, specifically deep and shallow groundwater sources and surface water from Lake Michigan. While the report identified Lake Michigan water as a viable source of drinking water supply for the east side of the City, since the sub-continental divide bisects Brookfield, the City would still be dependent on groundwater to serve its west side residents. Unfortunately for the City, the two water supply facilities exceeding radionuclide standards were located on the west side of the sub-continental divide, making the Lake Michigan option infeasible for those wells.

So the Utility searched for additional and alternative sources of drinking water, focusing primarily on shallow groundwater wells (sand and gravel or dolomite) in order to blend water from a new well with the wells that contained radium in excess of the standards. Unfortunately, the well closest to Brookfield Square with the most potential for this option was contaminated with vinyl chlorides, requiring the City to consider other options.

The Utility gamma logged the Brookfield Square well to determine where radium is entering the borehole with the hope that lining those areas with the highest radium content could result in the well meeting the compliance standard for radium. However, the analysis indicated that this was not possible without dramatically reducing the well's production rate. Losing capacity from this well was not an option for the City since the Brookfield Square well site represented one of the largest wells for the City and it could not afford to lose this source of supply.

The City of Brookfield Water Utility also proposed a radionuclide reduction process involving in-situ treatment of groundwater. This process would have given the Utility another option in the treatment of water for radionuclides; however, the proposal was rejected by the Wisconsin Department of Natural Resources (WDNR) as unpermittable.

The City recognized the unique challenges that it would need to confront at one of its largest well sites. The Brookfield Square well site was located in an established commercial area and next to a large, upscale shopping mall. Any facility constructed would need to incorporate architectural features and enhancements that would enable it to blend with the aesthetics of the surrounding structures and mall buildings.

The Water Utility had minimal space
to construct the new facility.

Consent Agreement
The City submitted a compliance plan to the WDNR indicating its inability to meet the radionuclide requirements by the original USEPA compliance date of December 2003. Fortunately, the Wisconsin Department of Natural Resources had decided to allow water utilities until December 8, 2006 to comply with the rule provided they enter into a consent agreement wherein those communities who did not comply would face legal actions and potentially significant fines. The City took the WDNR up on its offer and entered into a consent agreement for radionuclide removal from its drinking water. With the agreement in place, the City redoubled its efforts to find a feasible option for mitigating radium contamination in its wells.

Alternative Selected
Aware that the City's previous efforts to identify alternative sources of water or employ modest efforts to remove the radium from the water had been unsuccessful, the City sought assistance from the WDNR on alternative technologies. In addition, Tom Grisa, the Director of Public Works for the City of Brookfield started a grassroots group called Water Utilities in Southeast Wisconsin Treating Radium (WUSEWTR for short) so that group members could become aware of alternative radium removal technologies and to share the results of pilot testing performed at the various water utilities in the area. "This saved all utilities involved both time and money since we could learn from one another and didn't have to pilot test every technology at each utility", said Grisa.

WRT process schematic.

After a year of pilot testing the various technologies for radium removal and evaluating other utilities' results of their pilot tests, the City elected to use a new and innovative radium removal method provided by Water Remediation Technology, LLC (WRT), located in Wheat Ridge, Colorado. As employed in the Brookfield system, WRT's Z-88 system operates by passing radium-contaminated water through a fluidized ion-exchange bed of zeolite-based treatment media, a patent pending mineral substance onto which the radium attaches. Unlike other technologies, there is a minimal backwash cycle and all liquid backwash water is reused so there is no liquid waste stream generated by the system. In addition, no chemicals are added to the water so there is less chance of operator error. Finally, pretreatment for iron is not required.

Another significant advantage was that the WRT technology could also be installed and operated reliably considering the site constraints. With a total well pumping capacity of 1,300 gallons per minute (gpm), it was the first large scale municipal installation of the WRT radium adsorptive resin technology in Wisconsin. Previous installations had been constructed in Illinois and on the east coast.

"We looked at several different technologies that could suit our needs," said Tom Grisa. "WRT's process was cost-effective, was much easier for staff to operate and more stable than the others. In fact, other than making sure the equipment is still there, there is not much for our staff to do to keep it running. For us, it was an easy choice."

However, since this was the first time this technology would be used in Wisconsin, extensive pilot testing was required. The length of time required to complete adequate pilot testing and gainry approvals had already taken almost a full year. Once sufficient details about the technology were assembled, the City submitted its plans to the WDNR for approval. By December 2005, the City had gained WDNR approval and was finally ready to move forward with its radionuclide removal project using the WRT process. The City negotiated a long term (20-year) contract with WRT to remove the radioactive contaminant to a level below EPA requirements, providing the city with safe drinking water for decades to come.

Hurry up and Finish
In January 2006, the City retained Short Elliott Hendrickson Inc. (SEH) to design the site work and the building structure that would house the radium removal equipment. With the WDNR deadline of December 8, 2006 for completion looming later that year, the schedule became more critical with every passing week. The City and SEH held their first meeting to discuss the project's design concepts in February 2006. The City and SEH worked diligently with WRT to finalize the design concepts and started the final design process in April. Regular project meetings kept work moving forward.
Preliminary design drawings, including building elevations and detailed architectural renderings, were completed in time for a presentation at a May meeting with the City's Planning Commission. The WDNR was also kept in the loop to answer design questions since this was a new process and to facilitate a timely review once design was complete. Design continued to move forward at a pace that resulted in final plans and specifications being presented to the City by late June. WDNR provided timely approval of the design documents, allowing the project to be bid on August 3, 2006. The design phase was effectively completed in just three months from start to finish.

Treatment plant piping and equipment was recessed
three feet below grade for containment of radioactive
treatment media in case of a spill.

Construction would have to be completed in a similarly short timeframe if the City was to complete the project by the Consent Agreement deadline of December 8, 2006.

T. V. John and Son, Inc., from Butler, Wisconsin was awarded the construction project with a bid of approximately $410,000. A pre-construction meeting was held in late August, with ground breaking occurring in the first week of September.

To keep the project moving, the contractor elected to construct the walls of the facility prior to arrival of the fabricated steel treatment vessel. This would require a high lift over the 30 foot walls and careful placement of the tank onto the pad below. Despite some minor delays resulting from conflicts with underground utility and telecommunications infrastructure that share the site, the contractor completed the 650 square feet, three story high building and associated equipment installation, start-up and testing by December 7, 2006. Working together, the project team was able to complete the project construction in less than 90 days, allowing the City to achieve the EPA-mandatory compliance deadline with one day to spare.

Installation of the treatment vessel in late October 2006.

The treatment facility has been operational for one year and has performed as expected. Removal of radium from the water results in compliant water, and as expected, involvement from Water Utility staff has been minimal.

Once the media adsorbs enough radium to saturate it, it is replaced with new media. WRT is also contractually responsible for the environmentally safe handling and removal of the spent media from the treatment building to a licensed radioactive waste disposal facility. This required another round of negotiations with the Wisconsin Department of Health and Family Services, who regulates and permits the disposal of radioactive wastes. The level of radioactivity of the spent media waste generated from this process is extremely low. But once again since this was new to the state of Wisconsin, it took until March of 2007 to receive the actual permit to dispose of future waste, three months after the City completed the project.

The Sweet Smell of Success Since the project was completed and placed into service, the treatment facility has won several major awards for its design and operation including:

• the 2007 Environmental Project of the Year (projects under $2 million) from the Wisconsin Section of the American Public Works Association,
• the 2007 Engineering Achievement Award from the Wisconsin Section of the American Society of Civil Engineers, and
• a 2007 Water Utility Achievement Award from the Wisconsin Water Association.

The Brookfield Square Water Treatment Facility project is also a finalist in the running for the Grand Award from the American Council of Engineering Companies of Wisconsin that will be awarded in Spring 2008.