Lake options consideredPublished 11:20am Monday, December 17, 2012
Future plans for Lake Alice have been discussed by the Public Works and Safety Committee, and the City Council will hear options in January.
Interstate Engineering has studied Lake Alice’s water quality issues and recently presented several possible solutions to the Public Works and Safety Committee.
The study started about two years ago, and Interstate Engineering found phosphorous has contaminated sediment in the lake.
Several possible solutions have been proposed, but phosphorous removal will be a difficult, costly task, said city engineer Dan Edwards.
One option would be to dredge the most contaminated sediment out of the lake. This would likely provide the most immediate impact to improve the water quality, but it would also be the most costly, Edwards said.
Another option would involve flushing the contaminants out of the lake by pumping in clean water just as the ice is melting. Phosphorous separates from the sediment over the winter and could potentially be flushed out. This might be a more cost effective method, but it would take five to 15 years to make an impact.
All suggested solutions would total in the millions of dollars, and before any phosphorous removal projects can be effective, storm water drainage issues will need to be resolved.
Storm water that drains into the lake has led to the sediment contamination problem, and unless the lake is being fed by a clean water supply, good water quality will never be maintained, said Edwards.
“The storm water comes in carrying contamination, but it’s also a lot of water,” he said. “The lake could eventually dry up. Where can you get replacement water? Could you take it out of the ground with a well? Take it from the river? Those are all things that need to be answered.”
Sediment control and flushing are the two main options being looked at, but there are several others including combinations of the two and even creating an artificial wetland area to use nature to reduce phosphorous.
“No matter what we take, it’s going to be expensive, and financing is going to be a big issue,” Edwards said.
Interstate Engineering will present their findings and suggestions to the City Council Jan. 22, and a public comment period will follow. A copy of the draft will be available on the city’s website the first week of January.
Once input has been gathered and revisions have been made, a final report will be prepared and sent to the City Council for acceptance sometime next spring.