The Fenner Conservancy wanted to build an addition for expanded programming at the Fenner Nature Center in Lansing, Michigan.

An onsite system served the environmental educational facility and organizers wanted the same for the Susan and Jack Davis Nature Pavilion. On recommendations, they hired Larry Stephens, P.E., owner of Stephens Consulting Services in Haslett, Michigan, to design the system.

“The pavilion seats 100 people,” Stephens says. “I saw a unique opportunity to teach visitors the benefits of treating wastewater with everyday onsite components, then using the effluent to flush lavatory fixtures.”

He had the experience. In 1997, Stephens designed the first water recycling system in the state for a carpet store. Water meters documented the reuse of 80% of treated effluent. “With the pavilion’s modern fixtures, the percentage should be even higher,” Stephens says.

Officials liked the concept, but were concerned about cost and finding financing. Stephens, an officer with the Michigan Onsite Wastewater Recycling Association, presented the project as a training event and an opportunity to offer matching funds using proceeds from their annual conference.

The board agreed and members and manufacturers quickly donated materials, labor and equipment. “Except for the weather, the install went as smoothly as any project could go,” Stephens says.

Site conditions

Soils are loamy sand to sandy clay loam with a loading rate of 6.70 gpd per square foot.

System components

Stephens designed the system to treat 1,000 gpd. Major components are:

• 1,500-gallon polyethylene dual-compartment septic tank (Roth North America) with Biotube effluent filter (Orenco Systems)
• 1,500-gallon fiberglass dual-compartment recirculation tank with Biotube pump vault (tank and vault from Orenco)
• Two AdvanTex AX20 textile treatment modules (Orenco)
• 500-gallon Infiltrator polyethylene dose tank with 1/2 hp high-head pump (Orenco)
• Four multimedia HDPE sand filter containers with GSF modules (Eljen Corporation)
• Four Infiltrator ARC 24 chambers
• UV disinfection unit (SALCOR) and tablet chlorinator (Norweco)
• 1,000-gallon Infiltrator treated water storage tank with 1/2 hp high-head pump (Orenco)
• Three 3-by-12-inch-diameter Infiltrator Water Technologies EZflow drainage bundles
• Custom TCOM control panel (Orenco)
• Two water meters (Badger Meter)

 System operation

Wastewater from the pavilion flows 75 feet through a 4-inch sewer (all piping Schedule 40 PVC) to the septic tank, then to the recirculation tank. The 50 gpm pump in the vault discharges through a 2-inch line to the treatment modules. Effluent from the modules drains back through 3-inch lines to a splitter valve in the front of the recirculation tank. When the buoy is seated, the valve sends the flow 30 feet through a 3-inch pipe to the sand filter dose tank. When the buoy is open, the flow returns to the recirculation tank.

Fifteen times per day, the 10 gpm pump in the dose tank sends 60 to 70 gallons through a 1.25-inch manifold to each of the sand filter containers. Water trickling through the multimedia drains to the UV unit and chlorinator before entering the storage tank.

A pressure switch in the pavilion actuates the 10 gpm pump in the reclaimed water tank, sending up to 1,000 gpd 150 feet through a 1.25-inch pipe to a 30-gallon hydropneumatic bladder tank in the building. This water flushes the toilets and urinals. All other fixtures receive city water.

In case of high water in the sand filter dose tank or storage tank, a 4-inch overflow line runs 25 feet to the drainage bundles. Water enters through the tube in the center bundle, then trickles down to native soil.

Installation

More than 30 volunteers, contractors, and industry suppliers gathered for two days in the rain to install the system. Donations came from Milan Supply Co., Valley Farms Supply, Orenco Systems, Roth North America, SALCOR, Norweco, SCS Systems and Stephens Consulting Services. MOWRA matched the center’s $8,000 in out-of-pocket expenses.

“Most materials were delivered ahead of time, and we had two contractors working with us,” Stephen says. “Will Pitylak, owner of Pitylak Services, brought his Bobcat E85 mini excavator, an E63 mini excavator and five laborers to dig the tank holes. Mark Manyan, owner of Family Grade & Gravel, used his Bobcat skid-steer to move material.”

Laux Construction, the general contractor, oversaw job site safety. Stephens provided hard hats and coordinated installing the tanks in sequence followed by the AX20s, sand filter containers, storage tank and drainfield. Suppliers used the event to train and certify people on their products.

The sand filters drew the most attention. At the base of each 96- by 48- by 54-inch-high container was a gravelless chamber with end caps. A 4-inch pipe with rubber grommet was inserted just far enough into the downgrade end cap to drain the collected water.

The chambers were covered with 6 inches of fine bird’s-eye stone, 24 to 28 inches of medium to coarse filter sand, and topped with a geotextile filter module. The 1-inch distribution lateral on top of the module had three 1/8-inch holes with orifice covers (Sim/Tech Filter) at the 6 o’clock position. After covering the module with fabric, it was topped off with clean washed stone.

“Maximum overflow to the drainfield is 200 gpd, but peak use will be a rare occasion,” Stephens says. The drainage bundles were installed in a 12-by-4-by-1-foot deep trench.

The pavilion opened in mid-December 2019. Tours were part of MOWRA’s annual conference in January. “We’ve had a lot of positive feedback,” Stephens says. “The Fenner Conservancy is part of a national association and other nature centers are asking Liz Roxberry, the executive director, about the system.

“Public restrooms enable us to treat wastewater at the point of use and to reuse it several times before final dispersal or discharge to a sewer,” Stephens says. “Saving large amounts of water and energy is a concept the industry should be talking about.”

Maintenance

Mike Stephens of SCS Systems donated five years of maintenance. During the first four weeks of operation, a technician took weekly samples to verify proper disinfection. From then on, the system is being inspected quarterly and sampled twice annually to create a permanent record. The telemetry panel logs system functions and monitors meters on the reclaimed and potable water supplies to quantify the water savings.