Interested in Pumps?
Get Pumps articles, news and videos right in your inbox! Sign up now.
Pumps + Get AlertsThere’s an old saying: Make hay while the sun shines. But the West Jackson County Land Treatment Facility, in Ocean Springs, Miss., makes hay all year-round and uses biosolids and treated wastewater to do it.
The Jackson County Utility Authority collects dewatered Class B biosolids from three of its wastewater treatment plants, stores it on concrete pads, and then discs the material into 160 acres of utility-owned land to support the production of clover, rye grass, and crab grass. The authority then cuts and bales the hay and either sells or donates it to several users in the area. Treated wastewater irrigates the hayfields.
It’s a beneficial reuse process that has won awards, generates revenue, and effectively eliminates the need for other more costly biosolids handling methods. “We have a 10 mgd plant in Pascagoula, a 3 mgd plant in Escatawpa, and a 4 mgd plant in Gautier,” says Wayne Dennis, section manager. “Their flow schemes are similar, and the dewatered biosolids from all three plants are trucked to the West Jackson Facility in North Ocean Springs.”
Central site
The West Jackson Facility is actually the fourth treatment plant serving this area of Jackson County, which borders on the Gulf of Mexico. Constructed in 1986, it is an aerated lagoon system with a design capacity of 5 mgd and is being upgraded to 7 mgd. Current average daily flow is 3.5 mgd.
Wastewater is transported to the plant through a force main, then moves through two aerated lagoons in series. The first lagoon uses a Triplepoint Water Technologies submersible aeration system that can provide diffused-air, fine-bubble, and coarse-bubble aeration. The second lagoon has four 15 hp AEROMIX floating directional aerators. A third 5-acre polishing lagoon follows, providing a total residence time of about 45 days.
The authority pumps most of its treated wastewater to a 110-acre series of constructed wetlands planted with cattails. The wetlands went into operation in 1991 for secondary treatment and to reduce the nitrogen-ammonia levels in the discharge. Water depths range from 8 to 12 inches, and retention time is about 25 days.
Following the wetlands, the water goes to a common effluent ditch, which flows by gravity to the effluent pump station. There, two 60 hp Flygt (Xylem) pumps lift it to a contact chamber, where it is treated with chlorine, then dechlorinated and discharged under an NPDES permit to Bayou Costapia, which flows into the Tchoutacabouffa River and ultimately to Biloxi Bay.
About 900,000 gallons a year from the aerated lagoons is regulated by a no-discharge permit and irrigates the hayfields. A trio of Peerless vertical turbine pumps driven by GE motors moves the water to a spray irrigation system.
Beneficial reuse
While biosolids from the West Jackson Facility are removed from the lagoon bottoms only once every several years, it is the biosolids processing operation here that has drawn national attention and has won several distinguished awards.
Besides Dennis, the staff includes Raymond Ward, supervisor; James Roberts, lead operator; Damien Hosili, Dan Westerdahl and Jesse Spear, operators; Tommy Weaver, driver; Randy Coleman, compliance officer; and Shannon Clayton, maintenance supervisor.
“Our other three treatment plants aerobically digest their biosolids, with a residence time of 45 days,” says Dennis. “Then they thicken and dewater the material to about 15 percent solids on 2-meter Andritz belt presses. The cake is placed in 30-cubic-yard aluminum Travis dump trailers, which are pulled by one of two 410 hp Mack trucks to the West Jackson Facility, where it is stored on five concrete pads.”
The Pascagoula plant generates about 1,125 dry tons of biosolids per year, the Gautier plant about 490 dry tons, and the Escatawpa plant about 40 dry tons. Weaver picks up the biosolids cake and hauls it about 20 miles to West Jackson. The authority owns four Travis 30-cubic-yard dump trailers. The storage pads have a total capacity of 900 cubic yards, and the authority plans to build two more covered pads to increase storage capacity.
After each load, Weaver reports the cubic yards of biosolids hauled, the plant it came from, and the storage pad it was placed on. He then washes down the rig on a truck-wash pad so that none of the material is left to drop on the road.
“After they’re placed on the storage pads, the biosolids are tested,” Dennis says. “We check the fecal coliform, pH, TKN ammonia, and metals every two months. Our biosolids have to meet Class B standards, which means the fecal coliform must be less than two million colony-forming units per gram of total solids before it can be spread. Each field we spread on is limited in how much nitrogen it can take in a year, so we have to be careful not to overload the field.”
Feeding the crops
The authority’s acreage includes 16 plots totaling 160 acres. “If the sample results are OK, we apply the biosolids to the fields using a 170 hp John Deere tractor and a New Holland 12-yard manure spreader,” Dennis says. “Based on our permit, we incorporate the solids into the soil with a John Deere 15-foot disc harrow within six hours of application to prevent odors and vector attraction.
“We sample quarterly, making sure we remain above 6.5 pH on all 160 acres of the application fields. We also have groundwater monitoring wells that are sampled and analyzed on an annual basis for metals.” The authority reports the data twice a year to the state Department of Environmental Quality and annually to the U.S. EPA.
Before 2009, the primary hay crop was Bermuda grass. Based on its permit, the authority could apply 300 pounds of nitrogen per acre to that crop. That limited the amount of biosolids that could be applied and the authority frequently ran out of acreage. “Randy Coleman, our compliance official, developed a computerized site loading record system that tells us when we’re getting close to the nitrogen limit and closing out a particular field,” says Dennis.
As a result, the authority worked with the local university extension service to develop information on different crops that would allow an increase of nitrogen loading. “We found that by using clover as a cover crop, we could increase the nitrogen loading to 450 pounds per acre,” Dennis says. “That’s a 50 percent increase in capacity.”
Hay for sale
Today, West Jackson County only closes out about six of the 16 fields in a year due to nitrogen loading. “We’re still growing a crop that’s beneficial to the community, but now we can keep our fields in operation year-round because of the extra capacity,” says Dennis. “We are still in the early phases of this agricultural plan, but with the results we are getting now, I think it will be a win-win situation for everyone.”
When the clover crop matures, utility crews cut and bale it using a round or square baler manufactured by New Holland. The utility sells the round bales for cow hay for $35 a bale and the square bales for $5. Area contractors also use the square bales for erosion control, and the authority donates some to schools and community organizations for decorations at Halloween, Thanksgiving and other fall events. The revenue helps offset the utility’s costs to produce, cut and bale the hay.
The hay is sold at a competitive price that does not undercut other local suppliers. “Farmers really like it,” says Dennis. “It’s high in nitrogen content. They drive up in their own trucks and trailers and pick it up.”
Working with executive director Tommy Fairfield, the authority has applied for a U.S. Department of Agriculture loan of $850,000 to upgrade and expand its haying equipment. “We started planting rye grass, clover and crab grass in 2009,” Dennis says, “and it will take a few years to develop the crop to the point where we can manage it and schedule regular cutting.”
It’s a winner
The new equipment would allow the authority to harvest crab grass in the summer, and clover and rye grass in winter. “We’ll be able to keep our hayfield operation going year-round,” says Dennis.
The beneficial reuse program has drawn plenty of applause, both from local farmers and end-users, and from the wastewater profession and regulatory agencies. In 2005, the National Clean Water Act Recognition Awards Program honored West Jackson with second place in biosolids management for utilities handling less than five dry tons per day.
The award is based on several criteria, including advancement of technology, applicability of the technology to other communities, public acceptance of beneficial reuse, and dedicated individual or team effort. “It was an honor we appreciated, and we value it highly,” says Dennis.
With the improvements and advancements that West Jackson County continues to make, you can’t help but think they’d finish first if they entered again.