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� r <br />TO: Mayor and City Council ['u 12 <br />FROM: Mark Bernharr' ity Administrator <br />DATE: August 9, i9t <br />SUBJEC,r: Contribution Request - West _m Treatment <br />As you are probably aware the residents around West '-m have been <br />contributing over the last two summers to copper sulfate <br />treatments of West Arm in an effort to significantly reduce the <br />blue-green algae which grows there, in part becaue of the high <br />concentration of phosphates in telationsisip to nitrogen. The <br />effec' if there treatments is to actually kill the blue-green <br />microbiological algae organisms which is different than an alum <br />treatment, that settles out the phosphates thereby !--moving the <br />nutrients. The first treatment last summer and the second <br />treatment that took place this summer have been funded totally by <br />fun.' raising efforts of the ..si( -nts. Each treatment costs <br />bftween $4,000 and $6,000. The group hza. undertaken a third <br />treatment and about a week agc trade a phone request to City Hall <br />to see if the Council would be interested in making a <br />contribution. It was ind:-ated to them at that time that we <br />would explore it with the ncil and the related issues and ge <br />back to them, but suggestec iat they al­j discuss the -atter <br />with other communities tha. tie lake to see if the-, at;: <br />going to contribut.�. <br />The blue-green algae do-: not as such pose a p•ibl is health or <br />3fety problem and the .ii'ing of the blue-green algae results in <br />aesthetic benef it to the resi.'-nts on the lake. The tr�atrient <br />does however require that -i­ sw: ,ng be done in the trea-. ;area <br />fur approximately a week I_ .s generally anticipa !d and <br />c:pected that the treatmen. clears tta water possibly up to 5 to <br />6 weeks. <br />RECOMMENDATION <br />It is the staffs recom!-endat-*.n based on the information that we <br />have been able to gati,er in the -nsuin, seek that the funding <br />request be turned down r t�a.v fol .,wing .easons: <br />- Env i ronmenta_i - Whi 1,- substant i �, , a�T„>,;nt of d � to does <br />not exist regarding, copper sulfate treatment ? its <br />ramifications the Fresh Water Biological :nstivste is <br />presently undertaking a 3 ye-r. study to di-termitie what <br />impacts both short and lo. , teen that is does have. <br />W1.ilP copper is not as toxic as some of the heavier <br />-tale to ►..gher plant and animal forms, i' toxic to <br />eaictobiol,­,..cal organisms 5uc; as the b r algae <br />to the extend thatthese are in the fo(,,' chain may <br />.ave some further impacts u; a_nc chat - plu4 <br />interruptint, a step in the food chain. L is <br />Antir-ipatoi.' by the, residents that the r.opper su:.ate <br />1 <br />