The current Walden Ridge plateau plan, the Walden Town Center plan, and every other plan proposed over the past 30 years have lacked critical answers to the environmental challenges facing the mountain community. Simply mentioning issues related to sewage, traffic, stormwater, and unregulated development does not provide the necessary information to make effective planning decisions for the current residents of Walden Ridge, now or in the future.
Given the mountain's geology and the extensive history of coal mining on the plateau, geotechnical studies should precede any zoning or development in areas of known disturbance, landslides, or subsidence. Areas predicted to experience land failures over coal mines should be considered high-risk and restricted to park use (Avel letter 2023 provided to Walden, WWTA, and RPA).
The mountain's soils are very shallow, with little fluid retention and a shallow depth to bedrock, posing severe limitations to subsurface sewage treatment (Soil Conservation analysis, 1981). Therefore, self-contained sewage treatment installations should be denied or designed with the maximum drip field area to avoid hydraulic overload of the treatment sites with sewage effluent.
The Tennessee Department of Environment and Conservation Division of Water Resources has reported that one-quarter of all drip fields in the state have exhibited notable performance issues, including wastewater not being appropriately controlled, and another quarter being out of compliance with permit requirements. Systems on the mountain should be over-engineered or permits denied for unsuitable locations. TDEC also states that these drip fields have a finite lifetime, and fresh soils must be available for the treatment process to continue. The WWTA requires a redundant drain field that extends the life of the installation but is not an indefinite solution. The amount of acreage devoted to sewage treatment as drip fields is significant and is restricted from community use. This fact impacts everyone, and as more development spreads to rural areas, more community opposition should be expected.
Climate change is impacting all regions of the country, and historical values for rainfall, peak rain events, drought, and temperature fluctuations should be reexamined to calculate stormwater impacts, erosion, and infrastructure (roads, sewage lines, homes) vulnerabilities unique to the mountain environment.
Addressing these issues directly in development planning will result in a better plan. Allowing developers and installers to dictate or ignore these issues will continue to leave municipalities and homeowners to deal with the problems and costs of corrective measures long after the developers have taken their profits and moved on.
Tony Wheeler