In spring 2006, businessmen proposed developing a winery in the small community of Arrington, Tenn. Williamson County Department of Sewage Disposal Management (WCDSDM) officials met with Jeff Hooper, P.E., of Barge Cauthen & Associates of Nashville and Tim Turner, P. E., of T-Square Engineering Inc. in Franklin to plan the onsite system.
The primary issue was how to handle the high-strength winery wastewater containing fine particulates of grape and wine residues (called lees). County and state regulations had no guidelines for dealing with it, nor did they approve advanced treatment technologies for subsurface disposal. Without it, the drainfields would fail prematurely.
To enable pretreatment of the wine process wastewater, it had to be separated from the domestic flow, according to the design team. The goal was to lower production effluent BOD and TSS levels to that of domestic effluent. Tom Petty of Quanics Inc. provided design assistance, and Brian Corwin of WCDSDM provided regulatory guidance, since the county classified the pretreatment system as experimental.
Modeling wine production and general flow projection after Beachaven Vineyard & Winery in Clarksville, Tenn., Hooper and Turner designed a system using multiple settling tanks with effluent filters, media filter-type advanced treatment systems, and low pressure pipes (LPP).
Site conditions
Soils are well-drained Class III (silt-clay loam) to Class IV (clay-nonswell). The water table was not a concern, as the drainfield is on top of a hill. The 75-acre winery encompasses several pieces of hilly property. An older house on one section became the sales offices and testing facility. An extra-high-intensity soil map revealed a suitable location for the onsite system on the adjacent lot where the production facility was built.
Winery system components
The winery is expected to produce a maximum of 50,000 gallons of wine per year. The wastewater system is designed to handle 1,250 gpd. Its major components are:
• 2,000-gallon, two-compartment lees settling tank. All concrete tanks made by B&B Concrete Products, Columbia, Tenn.
• 1,500-gallon, two-compartment lees settling tank.
• Two, 1,000-gallon, two-compartment lees settling tanks.
• Four A600-12 effluent filters (1/64-inch filtration) with SmartFilter alarms from Polylok Inc., Wallingford, Conn.
• 2,000-gallon, single-compartment recirculation/dosing tank.
• 1/2-hp centrifugal pump with pressure filter inside a filtered pump vault from Quanics Inc., Crestwood, Ky.
• Two, 1,000-gallon BioCOIR advanced treatment units from Quanics.
• 3,750-gallon, single-compartment pump tank.
• 2-hp, multi-stage, turbine pump inside an effluent filter vault from Zoeller Pump Co., Louisville, Ky.
• 2.5-inch Schedule 40 PVC supply/manifold.
• 1,250 feet of 1.25-inch Schedule 40 PVC LPP laterals on 5-foot centers in three zones for the primary drainfield (7,068 square feet).
• 1,250 linear feet of 1.25-inch Schedule 40 PVC modified low pressure pipe (MLPP) laterals in three zones for the secondary drainfield (8,548 square feet).
• Two Hydrotek 6603 multi-zone distribution valves from Quanics.
• Control panel from SJE-Rhombus Controls, Detroit Lakes, Minn.
Domestic system components
The winery, which employs seven people per shift, has no mass food preparation capabilities and only a small employee dining area, so high-strength kitchen waste was not an issue. The flow calculations accounted for about 100 visitors per day. Turner designed the system to handle 640 gpd. Its major components are:
• 1,500-gallon, two-compartment septic tank.
• 1,500-gallon, single-compartment pump tank.
• 2-hp, multi-stage, turbine pump inside an effluent filter vault from Zoeller.
• 680 feet of 1.25-inch Schedule 40 PVC MLPP laterals on 5-foot centers, split into two equal zones for primary drainfield (6,208 square feet).
• 680 feet of 1.25-inch Schedule 40 PVC LPP laterals split into two equal zones for the secondary drainfield (6,693 square feet).
• 2.5-inch Schedule 40 PVC supply/manifold.
• Two Hydrotek 6602 multi-zone distribution valves from Quanics.
• Control panel from SJE-Rhombus.
System operation
Winery wastewater gravity flows through four lees settling tanks, which are expected to reduce TSS by 60 percent and BOD to a manageable level. Liquid then enters the recirculation tank, where dual stainless-steel screens in the pressure filter provide 1/20-inch filtration. The pump, which is on for two minutes and off for 10, sends 25.6 gpm to the ATUs.
There, microorganisms, attached to short and medium coconut husk fibers in the ATS BioCOIR units treat the wastewater as it trickles down. (The fixed media loading rate is 7.35 gpd per cubic foot.) The porous fibers also facilitate air movement. Effluent at the bottom of the treatment tanks gravity flows back to the influent end of the recirculation tank, then passes through a splitter built into the riser over the first access. The splitter recirculates 80 percent of the liquid to the recirculation tank and sends 20 percent to the LPP pump tank.
The BioCOIR units were chosen because they provide passive treatment and have minimal operation and maintenance requirements. They also can handle seasonal flows, as the winery’s process wastewater production is typically limited to a 60-day harvest.
During periods of low or slow flow, a float-activated diversion valve in the splitter directs 100 percent of the effluent back to the dosing tank, keeping the microorganisms moist and fed. Treated effluent is sampled where the discharge line from the splitter enters the first riser of the pump tank.
Primary and secondary drainfields, sized solely on hy-draulic demands, are 650 feet from the tanks and are elevated 75 feet above the pump in the pump tank. On demand, the pump sends 3.5 doses per day to the absorption beds. Each zone is dosed at least once every 24 hours.
The LPP system was selected because it decreased localized overloading, achieved uniform effluent distribution, and improved the soil’s aerobic conditions because the zones have rest cycles. The system also enabled the laterals to be installed in shallow trenches, thereby increasing the vertical separation from any potential restrictive soil layer.
Domestic waste from the sales offices/testing facility and winery flows into a septic tank and pump tank. Since Williamson County requires no pretreatment, the effluent disperses directly to the MLPP drainfield. Each zone receives one on-demand dose per day. A 40-foot buffer separates these beds from the winery’s absorption beds.
Installation
Jason Carter Backhoe in Fairview, Tenn., was subcontracted to install the onsite system. A dry period in February enabled Carter and five men to install the drainfields. Modified areas required incorporating 6 inches of topsoil into the native soil to achieve a depth of 30 inches to the restrictive layer.
“I’ve never installed drainfields like these with some sections modified and others not,” says Carter. “There wasn’t much topsoil on the clay, which was full of fist- to head-sized rocks.” The crew hand-picked them, while using a roto-tiller to work up the clay.
That night, it rained, and then the ground froze for two days, enabling Carter to truck in the topsoil. During the week of dry weather that followed, they dug 18-inch-deep trenches, laid the pipes, covered them with 12 inches of washed gravel, and backfilled with 6 to 8 inches of excavated material. The installation took six days.
The crew returned in mid-April to install the 10 tanks, and promptly hit limestone. A dynamite expert blasted the holes, but other contractors working on the processing plant complicated the positioning of the tanks. Three were poured onsite. The 3,750-gallon pump tank was too large to precast. The 1,500-gallon lees settling tank and 2,000-gallon settling tank went under the parking lot. They were poured with 6-inch reinforced walls and traffic-rated lids. Risers and lids were cast iron.
Maintenance
Williamson County required Arrington Vineyards to have a perpetual maintenance contract with an EPA Level 5 management entity approved by Quanics, and to draw quarterly effluent samples. Every six months, Jeffrey Cox, owner of IRM Utilities of Baneberry, Tenn., monitors the solids levels in the tanks and recommends pumping as necessary.
Technicians clean the effluent filters in the settling tanks and inspect the pumps. IRM checks the alarm floats, checks and cleans the pressure filter on the treatment tank pump, checks the BioCOIR modules for proper dosing pressure, and checks and cleans the spray distribution nozzles. The firm sends a report to Williamson County after every visit.
Hooper and Turner’s design is expected to achieve the project’s objective, lowering production effluent from 4,000 mg/l BOD5 and 2,000 to 3,000 mg/l TSS to less than 15 mg/l for both constituents.
Editor’s note:
This article is based on a paper, Fixed Film Pretreatment of Winery Wastewater Using BioCOIR, by Brian K. Corwin, Thomas C. Petty and Kevin M. Sherman, presented at the American Society of Agricultural & Biological Engineers’ 11th National Symposium on Individual and Small Community Sewage Systems in Warwick, R.I. in October 2007.
