The EPA has decided on artificial turf to cap a mountain of waste gypsum in Pascagoula that is now a Superfund site.
It will be cheaper and quicker to use up front and cleaner and easier to take care of in the long run, it said.
The process has already been hurricane tested at sites in three states. And the people in the neighborhoods near this one seem to be OK with it.
This is not a sports turf.
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It took years to develop this geosynthetic product that looks like grass, engineers say.
Mike Ayers, president and CEO of WatershedGeo, the company that offers the patented process called Closure Turf, helped develop it more than a decade ago as the answer to replacing and rebuilding damaged soil and grass caps on landfills and brown field sites.
He was in the engineering field for this type of work from St. Charles, La., to the Florida Panhandle and saw the need. His company will supply the material for capping the waste gypsum stack.
EPA made the decision after listening to public comments about its plan to clean up the Mississippi Phosphates site — a mountain of waste gypsum that produces more waste when hundreds of thousands of gallons of water hit the mountain and become acidic, then drain into holding ponds.
The savings with artificial turf, according to the EPA, will come because contractors won’t have to haul in as much dirt and materials as they would in a traditional cap, where you need 500 truck loads per acre and a lawn of grass.
Former City Councilman David Tadlock, who lives near the site, said, “People seem to be satisfied with the information the EPA presented.”
He said the key is that it’s going to be funded and the cleanup will start soon.
The monstrous project made the National Superfund list in January.
In April, the EPA announced the Trump administration is keeping Superfund a priority, and the cleanup would begin this fall, continue through 2020 and cost $71.6 million, plus $36 million for treating the wastewater runoff during cleanup.
They will close and cap the exposed gypsum stack east of Industrial Road and focus on the ponds at the older gypsum stack (already capped with live grass) on the west side of the road. The capping and cleanup will happen in three phases, each lasting about a year.
And when they are done, the state will no longer have to manage and store more than 500 million gallons of contaminated wastewater. The volume of future wastewater will be cut by 98 percent, because the runoff will be cleaner.
The process is to lay a membrane, a special plastic barrier, directly over the gypsum and then add the artificial turf over the liner to protect it. The turf will then be backfilled with sand to anchor it against the wind.
Ayers said the turf is UV-resistant, polymer grass that is engineered to last 100 years.
When rain hits a mountain covered in this way, the runoff is mostly clean, because it doesn’t carry the dirt it would in a traditional cap.
The savings is $6 million, broken down like this:
* $4.6 million in construction: No need to bring in 1.2 million cubic yards of dirt (about 43,000 truckloads) to cover the gypsum.
* $1.4 million in maintenance: No live grass to fertilize, water or mow.
Because the artificial grass system can be installed quicker, up to one year quicker, the EPA plans to save $40,000 a day in the cost of treating the acidic wastewater.
The EPA says the first phases of cleanup will be followed by a site-wide final cleanup.
Why is this so important?
Mississippi Phosphates made fertilizer out of diammonium phosphate in a process that used sulfuric acid. The by-product gypsum was cast aside in an ever-increasing mountain that has a lake on top full of nutrient-rich, acidic water.
When the company declared bankruptcy and stopped production in December 2014, it left more than 700 million gallons of the water, with a trust fund that was insufficient to pay for treating the mess.
In February 2017, EPA took over.
When the wastwater gets loose, it has a history of wreaking environmental havoc on the surrounding marsh and waterways.
It’s toxic to fish and other forms of marine life, and can cause fish kills and algal blooms that deprive the water of oxygen.
Currently, the EPA oversees wastewater treatment at a rate of 2 million to 4 million gallons per day, at a cost of $1 million per month.
With the heavy rains, it has already spent $23.4 million.