Someone recently told me, “Septic systems and sludge are not, of course, inherently interesting.”
I beg to differ.
Humans have a fascination with all things scatological. The book “Everyone Poops” was a runaway bestseller when I was a young mother, and ZooDoo, sold as a garden supplement, became quite a moneymaker for the City of Seattle.
The problem is that septic systems, human waste and, yes, sludge are buried in the backyard so we rarely see what’s going on. This Saturday, Sludge Fest will give Islanders an opportunity to see how some new on-site technologies work, how much space they need and how much they cost.
Some of the products are designed to fit on tight lots, such as shorefront properties.
There will be a see-through tabletop model of an aerobic treatment unit (ATU) on display. This system pumps air into wastewater, allowing the naturally occurring bacteria to consume organic matter and nutrients more efficiently.
Another system re-circulates the wastewater through textile filters before it is discharged into the soil.
There will be a demonstration of how one ATU is designed to fit inside an already existing septic tank. The manufacturer claims this unit can help refurbish failing drainfields.
And participants will see how a modern composting toilet looks right at home in the finest of bathrooms.
Many of the newly installed systems on the Island are discharging liquid wastewater effluent through drip irrigation lines that are installed only six inches deep. They look much like the watering system I have in my vegetable garden.
This technology makes a lot of sense to me because it discharges water and nutrients into the root zone for uptake by plants. It seems like there would be fewer opportunity for nitrates and other contaminants to get into groundwater when compared with deeper conventional drainfields.
I’m interested to find out how the manufacturers prevent the emitters from “blocking up” from particles in the wastewater or from roots trying to weave their way into the drip line. I also want to understand the fate of pathogens like viruses and bacteria in the effluent, particularly when it is discharged so close to the surface of the ground.
Two different types of drip irrigation lines will be on display.
John Thomas and Lee McIntire from Washington On-Site Sewage Association (WOSSA) will be on hand. They have seen it all when it comes to the design, operation and maintenance of septic systems. McIntire is a septic system designer and will give a presentation about the range of new technologies at noon. King County Public Health will have an on-site sewage program display, and Michael Laurie of Watershed LLC will provide handouts on low-flow utilities as a strategy to lessen the burden on septic systems.
There are several factors that have spawned a high level of community interest in septic system alternatives.
Our own septic solutions committee has been seeking affordable fixes for failing systems. The King County On-Site Septic System Management plan adopted in 2008 designated a marine recovery area (MRA) on the Island. The MRA affects 290 parcels and requires owners to inspect and repair or replace their on-site sewage system if needed by July 1, 2012.
The King County Groundwater Program recently received a grant from the Environmental Protection Agency to assess all of the nitrogen inputs into Quartermaster Harbor, including septic systems. And, a WaterWorks grant awarded to the Vashon Water Purveyors Association focuses on protecting our potable water supply.
Here’s an opportunity to take a look at septic system science up close. It’s interesting. Really.
— Susie Kalhorn is an environmental educator on Vashon.
Sludge Fest
Sludge Fest is 11 a.m. to 2 p.m. Saturday, April 18, at Chautauqua Elementary School. From noon to 12:30 p.m., there will be a presentation by Washington On-site Sewage Association about the range of technologies available and the design/permitting/installation process. Throughout the event, participants can check out displays and talk with vendors
It is co-sponsored by the Island’s septic solutions committee, groundwater protection committee, water purveyors association and the On-Site Sewage Association. It is funded in part by a WaterWorks grant from the King County Department of Natural Resources and Parks.
