The team at Boggs Water & Sewage in Virginia had a tight time frame to meet the opening date for a new water park along the Atlantic coast.

First of all, there was the site itself. Although it isn’t directly exposed to the ocean, Chincoteague Island sits right behind a barrier island that shields the mainland from ocean waves. Dig down a couple of feet on Chincoteague, and you’re in the water table, says Nathan Thornton, vice president at Boggs.

The water park was added at a large KOA campground on the island and joined other tourist attractions there. It was a new installation, so there was no equipment to remove or reuse. The plan called for the system to serve a Tiki bar, as well as a building with bathrooms, a store and a snack bar. It was a small expansion, only 6,000 gpd, but because of the potential for impact on the island and nearby water, the system had to emit BOD and TSS at less than 10 mg/L and nitrogen of less than 8 mg/L. Yet there is also plenty of capacity in the system to allow for an expansion of the facility, for example with a restaurant. McCrone Engineering designed the expansion dual-train BioMicrobics FAST system.

Dual train

Wastewater from the bar and service building flows through 4-inch Schedule 40 pipe to a collection station inside an 8-foot-diameter well. Two 2 hp grinder pumps (Liberty Pumps) send water through about 1,500 feet of 2-inch Schedule 40 force main to the treatment components. These were placed in a maintenance area on the edge of the property and away from the campsites and other public spaces.

The force main empties into a 6,000-gallon concrete equalization tank. Baffles inside slow down the surges. All tanks came from Gillespie Precast of Greenwood, Delaware.

A 6-inch pipe takes wastewater out through a SaniTEE filter (BioMicrobics) and into a distribution box. The box has six outlets for 4-inch pipes. Three pipes flow into one 4,000-gallon tank, three into another, and these tanks are the start of two identical treatment chains. The distribution box was a way to make sure the flow was evenly divided, Thornton says. Some flow levelers don’t do that, but this box has speed levelers like those in a drainfield so technicians could dial in a perfect split.

Inside the first 4,000-gallon tank in the train is a BioMicrobics MicroFAST 3.0 unit. Second is another 4,000-gallon tank holding a BioMicrobics NitriFAST 3.0.

Third is a 1,500-gallon baffled tank that recirculates water with a WE0311L pump from Goulds Water Technology, a Xylem brand. These are controlled by timers set according to need by the system operator.

Next is a BioMicrobics ABC-N 3.0 unit to convert the nitrate created upstream into nitrogen gas. This unit is housed inside another 4,000-gallon tank. This tank also has chemical feed lines for MicroC, a carbon source for microorganisms, from Environmental Operating Solutions Inc. (EOSi).

Last in the chain is a 2,000-gallon tank holding a MicroFAST 1.5 aerobic unit.

The flow from both treatment chains is combined and flows through four SALCOR 3G UV units and into a 6,000-gallon dosing tank. A pair of American Mfg. pumps send water through 2-inch force main to a headworks box with solenoid valves that alternately dose the dripfields. There are also valves that can route wash water from the dripfields back to the head of the equalization tank.

The dripfield is fed by 1-inch lines. Tubing was laid on sand beds. Technicians put about 2 feet of sand on top of the soil, laid the dripline and covered it with 6 inches of sand. Grass cover absorbs any remaining nitrate. There are four drip beds, each 50 by 36 feet.

A BioMicrobics NEMA 4X panel controls the treatment system. The drip system is controlled by an American Mfg. Perc-Rite panel.

Water, water everywhere

Because Chincoteague Island sits at sea level, one of the big issues the Boggs team had to deal with was groundwater.

“The dewatering of this thing was a lot,” Thornton says. “We put in a wellpoint system to cover the whole area.”

The working space was 140 feet long, 40 feet wide and 13 feet deep. It required 120 wells. Each was 1 1/4 inches wide and 16 feet deep. The pipes had 3 feet of screen on their ends and were drilled 3 feet on center. All the pipes connected to a manifold, and on the end of that was a pump (Godwin Pumps, a Xylem brand) to apply vacuum. Although the water table was at 2 feet, the wellpoint system dried the soil to the full system depth of 13 feet.

The team was ready to move in, but on the night before the job started, there was a freakishly strong storm. Thornton’s garage was damaged by a falling tree, and the storm left about 6 inches of water behind. It put the wellpoint system to the test.

He had to pull the points up a bit, from 18 feet to 16, and then they worked better. At 16 feet the sandy soil transitioned into prehistoric marsh mat. What you generally want to do with this kind of installation is keep the screen just below the depth of the cut, Thornton says. If you don’t, you may have a suction leak — pulling air into the system.

Schedule headaches

Tanks were not available until later in the spring, and if the whole project had waited on them, the customer would have missed the Memorial Day opening date. So the dripfields were built from mid-February to mid-March. Tanks went in later.

The pressure-sensitive sand beds created a restriction on one side of the site where the tanks would be buried. On the other side was a high-capacity power line about 24 feet away from the site. There was enough height under the wires for normal equipment to work, and some of the excavated dirt was stored there, but the power lines on one side and absorption field on the other created a narrow alley for equipment, especially the big crane needed to set tanks.

The team staged the work so it began at the end of the work area farthest from the access point. After a hole was complete, the crane moved in and the trailer with the tank on it came behind that. The crane set the tank and was moved out for excavation of the next hole.

Because of the power lines, the crane could not swing tanks in that direction. The only choice was to move tanks over the absorption field. And instead of a 70-ton crane, the job required a 100-ton crane because it was able to reach farther. Aerial Crane of Parsonsburg, Maryland, handled the job.

“The guy on the crane deserves a special thank-you. This needed some patience, and luckily he had plenty of it,” Thornton says.

Digging holes required care. Tanks were set about 5 feet from the wellpoints, which were just beyond the tapered soil of the absorption fields. Excavation walls were more vertical than he wanted next to the absorption field, but with the soil dried out, the structure held, Thornton says. “But you didn’t walk over there,” he adds.

For the blowers and panels, they built a pad shaped like a sofa. The seat of the pad is about 30 inches off the ground because Chincoteague is a low-lying island prone to flooding. Blowers sat on the seat of the pad. Panels were mounted on the back. A 200-amp service was installed to run the system.

Tank installation began on April 15. On May 15 the job was finished.

“There were some long days,” Thornton says. But the job was done when it needed to be done, leaving plenty of time for local inspectors to do their job and issue an occupancy permit and for Maui Jack’s Waterpark to be ready for the summer tourist season.