AUBURN — An updated analysis on proposed ordinance revisions in the Lake Auburn watershed predicts the changes could lower the amount of phosphorus entering the lake, but says to reach its overall goals, the upper watershed towns must make similar changes.
In a news release Tuesday, city officials said the analysis shows Auburn is on the “right track” with its proposed changes.
The city’s consultant, FB Environmental of Portland, updated its previous modeling based on proposals to change the septic system standard in the watershed, as well as move to a three-acre minimum lot size from a one-acre minimum. The proposal to lower the allowed density came in response to concerns that the updated septic ordinance would allow for more residential development.
The new septic rules would allow property owners to utilize alternative soils in designing septic systems — something that has not been allowed in the watershed, but has also restricted development. The initial report from FB Environmental recommended updating to a better performing septic design, but acknowledged the change would make more lots available to be developed.
In May, the City Council tabled a vote on the septic changes, instead sending it back to the Planning Board to consider a zone change for larger lot sizes and pursue the updated modeling.
Following the new analysis, city staff has recommended that officials implement both changes at the same time. The Planning Board held a workshop on the updated modeling Tuesday, which states that the city’s proposed moves would decrease the total annual phosphorus load to 937 kilograms annually. The report gives an overall goal of reaching 900 kg per year, which it says will likely rely on upper watershed towns like Minot, Turner and Buckfield to implement similar changes.
A memo from city planning staff said, “This proposed zoning change is not a solution on its own but would work with future proposals to limit phosphorus inputs into Lake Auburn. Increased phosphorus can cause water quality decline, leading to the need for a filtration plant that would cost millions of dollars and increase water bills within the city.”
The 2018 phosphorus load was 1,114 kg, which was reduced to 842 kg by 2020 following an application of aluminum sulfate. The report states that the 937 kg level has a “low risk” of triggering a waiver violation, but that 900 kg level would yield “no” risk.
The city’s effort to pursue the new septic ordinance, along with rezoning land along the Lake Auburn watershed boundary, has led to outcry from residents concerned about development that could impact the lake. It’s led to a petition effort, as well as “Protect Lake Auburn” lawn signs and a lawsuit from neighboring Lewiston.
The news release Tuesday said Auburn “has received confirmation that it is on the right track with proposed ordinance changes,” and that the city can move forward toward its goal of “modernizing lake protection ordinances by limiting density and incorporating best practices in phosphorus control and subsurface wastewater disposal in the Lake Auburn watershed.”
Mayor Jason Levesque said Wednesday that the city listened to residents’ concerns, and “took a smart approach, and then had it verified.”
“I’m happy to see all the work we’re doing is on the right track and will make the lake healthier,” he said, adding that now the city must “compel” its neighboring towns to adopt similar phosphorus controls. “We’ve done the hard work, and the controversial work. We’re not trying to damage the lake, we’re trying to enhance the lake.”
Responses to the news release on the city’s Facebook page Tuesday reflected the divisive nature of the ordinance changes. One person said the new analysis “does nothing to change” the “original recommendation of no more development in the watershed.”
The original report found “no net environmental, economic or social benefit supporting expansion of development in the Lake Auburn watershed.” However, among its recommendations was amending the watershed boundary along Gracelawn Road, and updating the septic ordinance.
A “build-out analysis” showing the projected number of buildings that could be allowed in the future under the changes estimates 85 in Auburn and close to 700 combined in the upper watershed towns.
According to the report, the analysis used the existing or proposed ordinances, existing natural features, and “other development constraints to estimate the number and location of new buildings possible under the simulated zoning.”
John Blais, deputy director of Planning and Permitting, told the Planning Board on Tuesday that the city should implement the septic design and lower density “at the same time to make this effective.”
“Those two items need to happen together for water quality, in our opinion,” he said.
Asked about getting phosphorus levels to be modeled lower than they are now, he said work is being done to identify sources of high phosphorus.
Levesque said the city will likely finalize the changes this fall.
The new Lake Auburn modeling can be found at https://tinyurl.com/3zhjnenw.
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