Little Pink Houses, Part II: Counties prepared for potential problems

Due to a rigorous maintenance program and regular testing, decentralized systems are less prone to catastrophic failures and, like their centralized cousins, are designed to serve a household for life, experts say.
Planning directors across the midstate explained there has yet to be a significant environmental risk posed by decentralized technology as none of the state's 183 existing systems has broken down.
In Rutherford County, where the use of onsite sewer treatment methods is most widespread, county planning director John Davis said the systems have experienced only minor problems.
"The only problem we have had is, until they get enough houses on (the system), they have a problem with getting enough water into the sand filters for them to work properly," Davis said. "In some cases, they've had to actually pump water into the system to keep the sand filters working right."
Williamson County Planning Director Greg Langeliers added the possibility of a failure is an ever-present concern although none of the systems in his county have experienced catastrophic failures either.
On some occasions, however, problems beyond the control of decentralized technicians do occur.
"Someone runs over your drip line with a tractor and plugs it up and creates a little ponding area and, somehow, a line breaks and that fills up with some treated wastewater, but is that a failure? Well, no. That's something where you get out there, and you repair it as best you can and go on," Langeliers said. "I'm sure failures happen pretty regular relative to those types of things and nozzles plugging up and what not."
Still, Water and Wastewater Authority of Wilson County Director Eddie Harris pointed out conventional septic tank treatment methods pose similar problems.
Those problems, he continued, have given rise to an entirely new form of decentralized treatment in Tennessee known as Advanced Treatment Systems (ATS). In such a system, wastewater undergoes similar treatment as that moving through an onsite system. In most cases, however, an ATS serves only one residence.
Five such systems are already online in Wilson County, and because of the failure of standard septic systems, more than 100 ATS installation applications have been submitted to Harris' department.
"Those things are helping people save their homes," he said. " … They're now being studied by the state (at the request of) the Legislature."
Experts in the field of onsite technology say with proper maintenance, a massive, systemwide decentralized system failure is unlikely. However, they are quick to note that, due to the systems' limited history in Tennessee, they are entering the field with caution.
"We haven't had any major problem, but the reality is that these have only been around since the late 90s, and we don't have 20 years of experience with them," said Ed Polk, a permit writer with the Tennessee Department of Environment and Conservation.
Polk admitted "very few" of the decentralized systems permitted by the State of Tennessee have failed to abide by the no-discharge permits they are required by law to obtain. Even in cases where some level of discharge occurred, he continued, there was no immediate threat to the environment.
"We do set some limitation on the discharge from the secondary portion to the land application and, occasionally, a unit will exceed one of those values. But, in general, those (limitations) are just there to ensure that there's good operation of the system. They're not there to say that if a value is exceeded a condition of pollution will exist," Polk said. "They're mainly just operational control parameters."
Built during the early part of 1999, the oldest decentralized system in Wilson County serves neither a sprawling residential development nor a commercial site. Instead, the five-year-old system was installed to serve a growing student population at Tuckers Crossroads Elementary School.
And, thus far, Harris said the system has operated year after year without incident.
One year after the construction of the Tuckers Crossroads system, onsite technology was used for the first time in association with a residential development as part of the Tinnell Station subdivision.
Four years into its operation, Harris explained the Tinnell Station system still works as if it were newly installed.
Were one of the county's systems to experience a problem between maintenance cycles, the issue would not go unnoticed. Here, as in other developments across the state, the systems are equipped with alarms that immediately notify water authority headquarters in the event of a mishap.
"If anything goes wrong, the system's going to let us know," Harris said.
Staff Writer Brian Harville can be reached at 444-3952 ext. 16 or by e-mail at brian.harville@lebanondemocrat.com.