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<br />. <br /> <br />. <br /> <br />. <br /> <br />.11. Bonestroo <br />e Rosene <br />"1\11 Anderlik & <br />1 \j 1 Associates <br />Engineers & Architects <br /> <br />2335 West Highway 36 · St. Paul, MN 55113 <br />Office: 651-636-4600 . Fax: 651-636-1311 <br /> <br />www.bonestroo.com <br /> <br />November 8, 2006 <br /> <br />Grant Wyffels <br />City of New Brighton <br />803 Old Highway 8 NW <br />New Brighton, MN 55112 <br /> <br />Re: Proposal for Step 2 and 3 Engineering Services <br />Water Treatment Plant No.4 Filter Rehabilitation <br />Bonestroo File No. 000335-06000-0 <br /> <br />Dear Grant, <br /> <br />The City of New Brighton is proposing to rehabilitate its Water Treatment Plant No.4 for <br />radium removal. This letter is our proposal for engineering services associated with Steps 2 and <br />3, which comprise the final design, construction document preparation, and construction <br />administration/observation phases ofthe Project. <br /> <br />Background <br /> <br />In 1986, following the contamination of the Jordan aquifer by TCAAP, the City drilled Well No. <br />10 in the Mount Simon aquifer to provide drinking water for the City. In conjunction, Water <br />Treatment Plant (WTP) No.4 was built to treat the water from Well No. 10. <br /> <br />In past years, WTP No, 4/Well No. 10 has been used as a "peaking plant" to provide water on <br />peak summer days for the City. However, as Kris Fluegel pointed out during our October 17, <br />2006 meeting, in the future the City will be depending more on WTP No.4 because of the <br />abandonment of Well No. 13. Water from Well No. 10 has radium concentrations of <br />approximately 6.1 pCi/L (picoCuries per liter), which is above the MCL (maximum contaminant <br />level) of 5.4 pCi/L set by the Environmental Protection Agency. WTP No.4 was not originally <br />designed to remove radium. As result, theCity is required to print a Notice of Violation in the <br />local paper every three months. In working with the Minnesota Department of Health, the City <br />has a "Return to Compliance" date of April 2007. <br /> <br />In anticipation of the April 2007 deadline, the City has added a "hydrous-manganous-oxide" <br />(HMO) chemical feed system to WTP No.4. The system consists oftwo chemicals, manganous <br />sulfate and an oxidant, potassium permanganate, which together form hydrous manganous oxide. <br />Radium tends to attach to manganese oxide (a solid), which is removed by filtration. However, <br />with the addition of the HMO chemical feed system, the City is still not achieving radium <br />removal. This is likely because the filter media is too coarse to capture the fine particles formed <br /> <br />St. Paul, St. Cloud. Rochester, MN . Milwaukee. WI · Chicago, IL <br /> <br />Affirmative Action/Equal Opportunity Employer and Employee Owned <br />