The Grove Wastewater Treatment Plant has been on-line for over 5 years now, but the plant has been working on turning the sludge into compost since last November. The compost facility is part of the Phase II Expansion Project which began in September, 2009. Grove Municipal Services Authority owns and operates the City’s Sequential Batch Reactor (SBR) Wastewater Treatment Plant. “I am really proud of both the Water and Wastewater treatment plants and the people who run them” said Jack Bower, Public Works Director.“The Wastewater Treatment plant is a great facility and we have great people running it” said Bower. He added that they have officials from other states and cities come to tour the facility. The compost facility is one of the newest in the area of total composting of waste water sludge.
“As populations grow, municipalities are forced to find solutions for treating increased volumes of wastewater. As more wastewater is treated, the wastewater solids separated during the treatment process create a new challenge, what to do with the increased volume of biosolids” according to Siemen’s Composting System Technologies, “Management of sludge or biosolids is one of the most critical processes in water and wastewater treatment”.
One solution is total composting of water sludge. “It’s only a matter of time that the landfills will stop accepting the loads” said City Manager Bruce Johnson. “It goes with the green theme taught to today’s school age children Recycle-Reduce-Reuse. We are only processing it and giving it back”.
Besides the green benefits the process also has economical benefits as well.
“Financially it is far cheaper to composite than to haul the sludge off” stated John Gibe, Treatment Plant Superintendent.
“Every time a truck filled with sludge left our plant it cost $800” he said, “We hauled off a minimum of three times per week.” Gibe said they will recover the costs of the compost equipment in 3-5 years. $600,000 was recieved by the Federal Stimulus Fund and Oklahoma Water Resources Board (OWRB) also helped fund the project.
“Plus we will be providing compost for free to the community”.
“Right now,” he continued, “Tahlequah is the closest facility composting waste water sludge and they are charging for it by the ton.”
Both Gibe and Johnson stated that there are several farmers in the area anxiously waiting for compost from the facility, however, Gibe said they won’t let it leave the facility until it has reached a Class “A” finished product.
“First and foremost, we don’t want anyone getting sick,” he said.
When asked when he thinks the rows will be ready Gibe stated that he recently sent off a sample that he is waiting for results of in the next week or so.
“I am feeling more comfortable that we will meet the requirements and be able to give compost to the public soon”.
What is composting? Composting is a microbiological aerobic process that consists of a 1:1 ratio mixture of Biosolids (sewage/sludge) and a carbon source such as wood chips (like the Grove Waste Water Treatment Plant uses). The carbon source is incorporated into the sludge. According to the Phase II Expansion Project overview for the treatment plant the static windrow will produce an internal temperature high enough to cause the destruction of pathogens that are potentially harmful to human populations. Rows must remain at 55 degrees C (131 degrees F) for 3 days. A row is turned eight times remaining at a consistent temperature.
After it goes through this curing process, the Grove plant screens it and takes out the large chips to produce the final compost that is to be tested. The whole process takes about 3 months per row. Once it is tested and reaches a Class “A” it will be safe for consumers.
A major part of composting is accomplished by the carbon source (which for this facility is wood chips). The plant currently has a contract with Asplundh to bring their in their chipper several times a year.
“We welcome any tree limbs that people want to bring here,” said Gibe. The plant is open for tree limb drop off 7 a.m. – 2 p.m. daily. There will soon be signs to direct residents to where they can drop off their limbs. “We currently have two years worth on site now, but can use more.”
Gibe also commented that anyone that wants to come out for a tour is more then welcome.
The facility will work year round to produce compost. In the winter, rows will be insulated with plastic or a special cover that will keep the process going. They will continue to check each row two times daily, once in the morning and one time in the evening. The also keep a log of each check.
To reach John Gibe, Water/Wastewater Treatment Plant Superintendent call 918-786-4177 or the City of Grove 918-787-5385.