Then a business in Cassville, Indiana, changed hands, the local health department wanted changes. Wastewater from the gas station, as well as a nearby house, was emptying into a drain tile that discharged into a county-regulated ditch that in turn discharged into a creek. The health department required a modern onsite system for both business and home.

The county approved a permit for the house. The gas station was more complicated, and both buildings were on the very same small parcel of land. “We had about 4/10ths of an acre to work in, including land for the buildings, parking and driveways,” says installer Dick Blazer, owner of Blazer Farms, Kokomo, Indiana.

That wasn’t the end of complications. Underlying the soil, about 47 inches down, is glacial till. Blazer had to stay out of that. This part of Indiana also has a very high water table, typically 8 to 12 inches. And a couple 100-foot well setback zones from neighboring properties intruded into the space Blazer had to work in.

Finding a solution

Because of the size of the lot and the service station owner’s plan to eventually serve food, the county specified an Aero-Tech aerobic treatment unit. Final treatment is done with an Advanced Enviro-Septic system from Presby Environmental.

From the rear of the gas station, effluent flows about 10 feet through 4-inch Schedule 40 PVC pipe into a 1,500-gallon, two-compartment concrete tank from McCreary Concrete Products in Rushville, Indiana. The tank is divided in half, and both sections settle solids. A filter at the outlet intercepts particles before water flows by gravity about 8 feet into a 2,000-gallon fiberglass trash tank from Aero-Tech. A Zoeller E-57 pump time-doses wastewater into the 2,000-gallon Aero-Tech fiberglass ATU tank.

An Aero-Tech pump next moves water into a 1,500-gallon concrete dosing tank from McCreary. Two Liberty 250 pumps, controlled by a panel from Aero-Tech, alternately send water out to the Presby sand beds.

Water is dosed through 1 1/2-inch Schedule 40 PVC to a spider valve. This was a change from the engineer’s drawings because the distribution boxes originally specified would have required being set 3 feet above ground in order to get proper gravity filling of the lines. The spider valve can accommodate orifices of different sizes to allow precise dosing of each bed. There are three outflow lines, one for each absorption bed. Two lines use 3/8-inch holes, and one needed an 11/32-inch hole. The spider valve is covered by a Tuf-Tite riser and lid for servicing and adjustment. Tuf-Tite products were used throughout the project except on the Aero-Tech tanks, which came with their own risers and lids.

The absorption beds are composed of three 60-foot runs of Presby AES pipe. Each bed is 62 feet long and 20 feet 6 inches wide, and has a 3-1 slope ratio. Below the Presby pipe is 12 inches of sand. Above is 6 inches of sand, capped with a foot of topsoil.

Blazer graded the rest of the property to make swales directing surface water around the beds. He also installed a perimeter drain with a 6-inch tile running 10 feet outside each sand bed and 24 inches below it to intercept the high groundwater. Indiana code allows this to ensure absorption beds are not flooded.

The house received a simpler system. A 4-inch line runs from the rear of the house into a 1,500-gallon partitioned tank from McCreary. The 1,000-gallon section provides septic treatment, and the other 500-gallon section is a pumping tank. A Liberty 250 pump controlled by a float sends water about 80 feet to the home’s front yard, where there is another Presby bed that is 62 feet long and 16 feet 2 inches wide. This also received a perimeter tile to intercept groundwater.

Necessary precision

“We were right down to the absolute inch on installation,” Blazer says. The space was already tight, and he found reality did not match the plans. A restricted well zone from a neighboring property was marked at 12 feet from the gas station property line, but it actually intruded 32 feet onto the property. “We had to scoot everything over to make it fit, and we curved bed No. 2 slightly to fit the space.”

Then there was the tree in front of the house. “The owner didn’t want the tree taken down, and I don’t like to take them down, but we had to trim some roots in the way of the bed and the perimeter drain for the bed.”

With no room to store material on site, sand for the beds was piled next to the street and moved to the rear of the property as needed to build the Presby beds. “We don’t drive tracked equipment on a bed because we’ve seen the damage it can do. You can pretty well pack all the sand down even under tracks,” Blazer says.

Sand beds should properly be built from the uphill side, Blazer says. To do that he uses a tool he fashioned for himself years ago. It’s a metal trough about 2 feet wide, 18 inches deep and 10 feet long, and it fits on his Kubota 80 GX excavator. It accepts a whole bucket of sand from his Bobcat skid-steer, and the Kubota operator uses the trough like a big scoop to sprinkle sand where it’s needed to build a bed. As Kubotas grew larger over the years the trough was lengthened to match, but the original cost of the trough was about $250, Blazer says.

Restoration was done with 27 loads of topsoil. Blazer’s Land Pride seeder, attached to the Bobcat with a homemade hitch, spread a mix comprised of a large portion of rye with some fescue and bluegrass. The rye sprouts and grows quickly to hold soil in place. In subsequent years the slower-spreading fescue and bluegrass take over and provide a lasting cover, Blazer says.

Even with the advanced system in place, the gas station is not yet meeting the owner’s full business plan. Originally that plan called for a simple kitchen to heat or fry prepared food and serve it, but the state did not approve that part because the wastewater system installed had to be smaller than usual to fit the available land area. The state wants to ensure the system has sufficient capacity, Blazer says, so he is monitoring the effluent strength for a time.

“There is no other option for this property. Without this system the property would have to have been condemned and the business closed,” Blazer says.