Part 1: Wastewater treatment seeps into the news again

by Don Audette, 29 June 2005

Every day, water and really gross stuff disappears down a drain from your toilet, dishwasher, kitchen sink, shower, bathtub, automatic dishwasher, bathroom sink, garbage disposal, etc., vanishing as if by magic. It goes away, never to be seen again. Where it goes is called a wastewater treatment system, which treats the filthy mess and disperses it.

This is a delicate matter.

There are two kinds. The wastewater trade calls them "centralized" and "onsite/decentralized" systems. The centralized ones are for cities, towns, densely populated counties, and major subdivisions. They involve large sewer pipes that carry wastewater far away from a home or business to a managed wastewater treatment plant where effluent (treated wastewater) is usually dispersed by discharging it into a river.

The other kind, the "onsite/decentralized" systems, treat and disperse wastewater locally, right in your back yard, or, if you are part of a small clustered development, close by.

Take Clevenger's Corner along Route 211 near Rappahannock County as an example of a centralized system. The managed wastewater treatment plant for this large development in Culpeper County is being designed to discharge up to 600,000 gallons per day of treated effluent into the Rappahannock River.

Is there a way to visualize this amount? A gasoline tanker truck, refilling a gas station, holds about 10,000 gallons. Visualize 60 truckfulls.

Longlea, right next to Rappahannock County on Route 522 and zoned by Culpeper County for 1,000 homes, a conference center, and commercial development, is in the news lately. A request for a use permit to build a managed wastewater treatment plant to discharge up to 450,000 gallons per day of effluent into the Hazel River has been tabled by Culpeper County's Board of Supervisors until September. 45 truckfulls.

A Big Dog, the Fairfax County Wastewater Treatment Facility, has 3,200 miles of sewer pipe. This managed system processes 100 millions gallons of wastewater each day, discharging it eventually into the Potomac River. 10,000 truckfulls.

In Sperryville, Rappahannock County's only publicly managed wastewater treatment plant has a permit to discharge up to 150,000 gallons per day of effluent into the Thornton River, but the current discharge is about 75,000 gallons. 7.5 truckfulls.

The key word here is "managed." Centralized systems involve people on payrolls. They design, construct, operate, and maintain such facilities to meet Virginia wastewater treatment performance requirements. They involve people who have been trained, tested, and certified or licensed, and who monitor the performance of the system. Centralized systems cost big bucks. The homeowner or business pays a significant "connection" or "tap" fee to hook up to them. Customers also pay a monthly or quarterly usage fee.

Onsite/Decentralized Versus Centralized Wastewater Treatment

Now we come to the second kind of wastewater treatment facility, the "onsite/decentralized" systems. The basic form is the traditional septic tank and its drainage field, handling about 300 gallons of wastewater per day. It is a passive system, no moving parts. It just sits there underground, doing its thing. Flush the toilet and the stuff does not travel miles away via sewer pipes to be treated. Everything happens in your backyard, including the dispersal of the effluent. Usually, liquid from the septic tank drains downward into your property via an underground drainage system, to seep through the soil, called an absorption field, to be cleansed. All that is called primary treatment.

But over the last 25 years there has been a movement to add secondary, even tertiary, treatment capabilities to some septic tanks. They make use of units with a mix of pumps, filters, alarms, stirrers, drip or spray units, disinfection units, chemicals, etc. Called alternative or innovative treatment devices, their purpose is to further cleanse effluent.

These units can be used for the remediation of failed or failing septic systems. EPA estimates that between 10 and 20 percent of septic systems in the U.S. fall into that category and are threatening to contaminate groundwater. They also can be used on smaller lots, on rocky soil, or on so-called "unbuildable" lots. Or they can be used for clustered homes and/or businesses, where they are called "packaged" wastewater treatment plants. But alternative/innovative units are not amenable for use everywhere.

In some units, the cleansed effluent results in surface discharge onto the ground or into nearby surface water, and some manufacturers claim the effluent emerging from their equipment is so pure that it is drinkable.

The Town of Washington is looking into a "packaged" wastewater treatment plant, with surface discharge into the Rush River. In environmentally sensitive areas, though, surface discharge is questionable.

The Chester Gap Special Exception Request

The request for a special exception for an onsite/decentralized wastewater treatment system by a landowner in Chester Gap involves a secondary treatment unit with surface discharge. It is for a new home, and not for remediation of a failed or failing septic system of an existing home. This is something new for Rappahannock County, a precedent-setting situation. [The request was denied by the Rappahannock County Board of Supervisors in July.]

As in centralized systems, the key word with onsite/decentralized systems is "management." Currently, the manager of a traditional septic system is the homeowner or business owner. They pump out the septic tank every three to five years. But when alternative or innovative treatment units are involved, management becomes complex.

And this is a delicate matter.

Take a Break: A Little History

The idea of a septic system goes back to 1881, when it was developed by a Frenchman. In a tank, he had "observed that part of the feces went from the solid state to the liquid state when the wastewater from toilets and sinks was allowed to remain in a watertight container." Supposedly, the local parish priest was so impressed by this discovery that he built a septic tank with a glass wall in his church so he could watch this action. His observations intrigued both the scientific community as well as his parishioners, who were undoubtedly appalled.

The idea spread, was patented by a British inventor in 1897, but did not catch on big in the United States until the early 1900s.

According to the U.S. Census Bureau's American Home Survey of 2003, there are now almost 106 million occupied homes in the United States. Some 84 million are hooked up to a public sewer plant, a centralized system. But close to 22 million make use of septic tanks, cesspools, and chemical toilets, e.g., onsite/decentralized systems.

In correspondence with Mr. Anish Jantrania of the Division of Onsite Sewage and Water Services, within the Office of Environmental Health Services, of the Virginia Department of Health, it was estimated that there were about 3,300 onsite systems in Rappahannock County in 2000.

No one knows for sure exactly how many failed or failing septic systems are in Rappahannock County. There are also failed or failing systems in the Town of Washington; the main reason the Town is seeking a "packaged" wastewater treatment plant.

"Who's Your Daddy?"

State and local regulations for traditional septic systems are up-front. Does the soil perc? Is the drainage field away from groundwater? Is it away from natural or manmade surface water? Once in, there are no inspections or monitoring unless there is a request, a complaint, or a transfer of property.

Now comes the wide variety of alternative and innovative treatment units, with their hydraulic and electrical parts, plus other components needing monitoring and maintenance. Everyone is covering themselves legally: the builder; examiner of soil; manufacturer; installer; homeowner or business owner; inspector; parts supplier of mechanical and electrical components; the person or company in charge of maintenance and monitoring; federal, state, and local regulators, etc. When something goes wrong, who is in charge? Who is responsible?

The wastewater trade and government have come up with the answer: the Responsible Management Entity (RME). Where do you find one?

This is the most delicate matter of all.

©Times Community Newspapers 2005. Used with permission.

Read Part 2: The dilemma of wastewater treatment management

Related article: Wastewater treatment goes high tech

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