FAYETTEVILLE -- Consultants presented a resident-led city panel potential ways to clean up Lake Fayetteville, but said more extensive work would be needed to have a lasting effect.
Brad Schleeter and Aaron Boll with engineering firm Olsson on Monday presented to the Environmental Action Committee the results of a yearlong study to improve the water quality at the lake. The City Council used $201,840 in federal pandemic-era American Rescue Plan money to pay for the study. The committee took no vote but asked questions.
The consultants recommended six ways to help clear up the lake within about five years. Initial cost of the methods would be about $6.8 million if implemented all together, with additional money needed for upkeep in subsequent years. Total cost to implement all of the methods over the next 15 years would be about $9.8 million.
All of the methods are efforts that would be done within the lake itself. However, to have a lasting impact, more work would need to be done within the larger watershed, reaching beyond the city limits, to lessen the amount of sediment feeding into the lake.
Long-term methods taking more than 10 years to implement could include stream-bank stabilization, creating conservation areas, building regional detention ponds and restoring riparian corridors. Hydraulic dredging and mechanical excavation could cost more than $17 million over the next 15 years, and the consultants ranked the method last among other recommendations.
The consultants also suggested getting participation from neighboring municipalities to push proper lawn care and pet waste disposal, as well as low-impact development and planting native vegetation.
Among short-term solutions, the consultants ranked aeration the highest. The process would introduce oxygen into the water with four compressors around the lake. The compressors have weighted hoses with diffusers on the ends that would sit at the bottom of the lake. The drawback, Boll said, is they require continuous operation. Initial cost to install the compressors would be nearly $1.6 million, followed by about $1.3 million in operational costs over the next 15 years.
Treatment with aluminum sulfate, a non-toxic material used to treat drinking water, would bind with soluble phosphorous and settle to the bottom of the lake. The "blanket" formed would prevent the release of phosphorous from the lake bottom. The method ranked second among the consultants' recommendations and would cost about $833,000 over the next decade.
Creating a channel where Clear Creek narrowly feeds into the lake from the northeast would catch much of the sediment flowing in, Boll said. The wetlands created as a result would help add native vegetation. Initial cost to do the work would be nearly $1.7 million, with about $260,000 worth of channel maintenance in the next 15 years.
Building a sediment forebay, meaning a small basin where water could be filtered before going into the rest of the lake, on the southeast corner of the lake, would capture nutrients from the Hilton Branch watershed, Boll said. Creating the forebay could cost about $1 million, with an additional $250,000 of maintenance necessary after six to 10 years.
Suspending bags of charcoal with buoys near the marina would have a limited, but effective, cleansing impact, Boll said. Cost would be about $376,800 over 15 years.
Lastly, parks employees have floated an idea to renovate the marina with the idea to increase recreational access, improve plant and wildlife habitat diversity and deflect algal mats from the most used part of the lake. The consultants estimated the budget for the project at more than $2.1 million, with about $25,000 in yearly maintenance necessary.
On the web
Read a summary of the Lake Fayetteville report from Olsson:
Read the full report at: