A site south of Ponchatoula is dead center in a lengthy debate over a controversial wastewater treatment technique. And the city of Hammond, though it lies well seven miles to the north, is deeply involved in that debate, thanks to a treatment system that discharges the city’s wastewater into protected marsh.
On either side of the debate are residents and stakeholders who each say they have science on their side. And watching from Baton Rouge are two state agencies responsible for permitting Hammond’s so-called “wastewater assimilation” operation. Both are reviewing the city’s effort to build and maintain a wastewater pipeline — which runs from Hammond to the site along the marsh — and its struggles to keep its discharge within safe, legal limits.
The Lens has confirmed that the agencies — the Department of Environmental Quality and the Department of Natural Resources — are investigating Hammond’s wastewater assimilation system after several years of shortcomings in treating the water that it discharges at the edge of the Joyce Wildlife Management Area.
Hammond’s discharge pipe itself extends about 6.4 miles from the South Sewage Treatment Plant in south Hammond to South Slough — a long canal running west to east, just north of the northwest corner of the Joyce Wildlife Management Area. The City of Hammond owns the land along South Slough on which the pipeline sits and where it discharges the treated wastewater. The neighboring wildlife management area is overseen by yet another state agency, the Department of Wildlife and Fisheries.
The wastewater assimilation method — its proponents prefer to call it wetland assimilation — is designed to provide a cost-effective alternative to standard wastewater treatment systems.
“The ability of wetlands to perform certain water purification functions has been well established for natural watersheds,” reads an excerpt from a use attainability analysis written in 2005 by Comite Resources, the private firm that designed Hammond’s system and several others across south Louisiana. “Studies in the southeastern United States have shown that wetlands chemically, physically, and biologically remove pollutants, sediments and nutrients from water flowing through them.”
The practice as currently permitted has been used since the early 1990’s in communities across south Louisiana. DEQ has even promoted the technique, listing 11 municipalities on its wetland assimilation web page.
Proponents say that because the sewage and stormwater is rich in nutrients, assimilation has the added benefit of helping to rebuild wetlands that have been hard hit by natural and man-made factors, including canals built for forestry, oil & gas production and highway construction. The flow of the wastewater, called effluent, also serves to keep saltwater out of freshwater marshland.
But that wastewater must be properly treated before it’s discharged. And that has been part of the problem in the City of Hammond and other towns using assimilation techniques.
The Hammond pipeline began discharging into the marsh in 2006. The city, which formerly discharged its wastewater into Ponchatoula Creek, had been cited by the DEQ for failing to comply with state limits on effluent content in the treated water prior to that. Since the assimilation program went online, it’s been cited dozens more times.
Opponents of assimilation, in Tangipahoa Parish and elsewhere, say it actually harms wetland environments and can take away some of the protections the marshes offer against extreme weather events. In the face of that criticism, the DEQ says it is reviewing the impact of assimilation systems across Louisiana.
The wrong kind of green
On a chilly March morning — Lundi Gras, to be precise — Ed Bodker crouched on the edge of the Joyce Wildlife Swamp Walk, south of Ponchatoula, and drew vials of murky water.
“I’ve been taking this test for 10 years,” he said. “And it consistently shows the same thing, except that originally it was much more.”
The test was an off-the-shelf test kit for ammonia. He drew samples from three sites along or near the Swamp Walk, sites that sit about a mile from the long pipe where the City of Hammond discharges wastewater from its sewage treatment system.
Bodker, a Ponchatoula resident who grew up in the region, said the sites he took these samples from are where water draining out of the marsh flow into the nearby canal along Interstate 55.
“The purpose of putting it in that marsh was for it to spread out over a large expanse,” he explained. But some of that water “short circuits” from the spread and finds its way toward a nearby canal, he said.
Two of the three vials of water turned a dark, rich green in color after a few minutes in the testing solution. According to the kit’s test strip, the color indicated the presence of ammonia or ammonium ions between 4.0 and 8.0 parts per million, at the top of the consumer-grade testing metric. The third, taken the furthest from the discharge site, turned greenish yellow, suggesting a lower ammonia presence between 0.5 to 1.0 ppm.
“I have literally spent days at a time, out in a pirogue in that marsh, taking hundreds of these samples to map where the water was going,” Bodker told us. “As dramatic as this shows, I can’t get anybody to come down here officially with me to show them that.”
Ammonia matters in a wastewater assimilation context because its presence in discharged water indicates potential eutrophication. That’s what happens when elevated levels of nutrients — such as nitrogen, of which ammonia is one form — promote increased growth in some, though not all, forms of vegetation and especially algae.
“Prolonged or excessive nutrient loading may adversely affect the assimilation area, with organic decomposition and loss of root matter contributing to decreasing soil stability and shearing,” wrote the authors of a 2017 paper for the Lake Pontchartrain Basin Foundation. “Recent research suggests that nitrogen enrichment accelerates plant decomposition in freshwater marsh.”
Bodker, a retired environmental manager from the La. Department of Transportation and Development, has railed against the impacts of the Hammond wastewater assimilation system since it began service in 2006.
He said one issue with excessive nitrogen levels is that they promote grass species that are annual in nature — they grow from seed and die within a year. Those annuals don’t promote firm soil development as well as perennial grasses, which regrow each year.
“Some species tolerate that ammonia better than others,” Bodker said. “And mostly that’s floating species, which don’t have roots and so you don’t have the roots holding it all together.
“I guess a lot of people don’t understand why I’ve taken this cause on so much for so long,” Bodker said as he boated up Anderson Canal, running west of the interstate, to show off a control marsh — an area of the marsh with strong perennial growth that is far removed from the Hammond discharge point. “Not only did this marsh mean a lot to me, when I was growing up, but the implications are much broader than just this one little spot. People don’t realize that the nutrient pollution worldwide is just an unbelievably large problem.”
Bodker stopped the boat on the canal at a spot next to a wide area of grassy marsh. “That marsh mat is 1,100 years old,” he said, “which is the general age of all these marshes.”
Wearing hip waders, he stepped carefully through a patch of cutgrass along the canal bank until he came to the firm mat of the marsh, covered in great part by a perennial grass called maidencane, or Panicum.
“It has a really strong root system, just like wire,” he told The Lens. “It holds that marsh together. And it’s been holding that marsh together for hundreds if not thousands of years.”
Bodker moved several yards into the marsh and selected a portion of soil to cut into with a large cane knife.
“This is the marsh mat,” he said after hauling the plug back to his boat. “It generally runs in between 30 and 50 centimeters thick. And you can see the living roots. And this other stuff” — referring to the soil clinging to the Panicum roots — “is old, real old, and the living roots hold it in place.”
Bodker said, when those living grass roots die, they lose their ability to hold soil together. “It would be loose,” he said, “which is what happened in the sewage marsh.”
The difference between tight marsh soil and the looser, watery muck found in swamp regions is a key factor in terms of stormwater protections.
Bodker said the Panicum roots held up fine when Hurricane Katrina hit these marshes, before the Hammond discharge began in 2006. But after wastewater assimilation began at the edge of the Joyce Wildlife Management Area, hurricanes such as Isaac, Gustav and Ike blew through and left stormwaters four to five feet in depth in parts, he said, raising up big clumps of loose soil around the area near the discharge pipe.
“All the marsh gases got in there and became buoyant during that high water,” he said. “And then the wind and all lifted big islands up and small islands and lifted up and blew it over. And when the water dropped, those islands fell down on top of the old marsh mat.”
That left big clumps of weak soil piled up in spots. “If you were to look out there and see stuff growing, you’d say, well, that looks pretty good,” he said. “But it’s not uniform,” like the control marsh to the west. “The mat is compromised.”
Bodker said the sewage discharge into the marsh neighboring South Slough changed what was once a uniformly vegetated marsh. Now the area is swampy, dominated by annual plants such as cutgrass and floating vegetation including pennywort, a perennial also known as Hydrocotyle that grows well in sewage ditches. Some of the vegetation is water hyacinth, an invasive species. And there are large patches of open water, offering much less protection for residents north of the area against storm surge from Gulf hurricanes.
“I have literally walked across the marsh before the sewage, many times,” he said. “In fact, when I was a boy, my friend had trap lines all the way around the marsh. And muskrats used to live in the marsh. They don’t have any in there now.“
He noted that deer, once common in the area, also are absent now, not being able to move through the swampy area. “It bogs them down just like it would you and me,” he said. Patches of sharp-edged cutgrass also present an obstacle.
What does well in the sewage marsh, Bodker said, is algae. In a 2010 presentation to the LPBF, he documented large blooms of green and blue-green algae, including one that sprawled over a 50-acre area.
“This type of green water is typical in oxidation ponds,” he wrote in that presentation. “This favors accelerated decomposition and destabilizes populations of denitrifying bacteria.” Denitrification is the removal of nitrogen and nitrogen compounds such as ammonia, in this context, from the soil. It’s performed naturally by bacteria.
The U.S. Environmental Protection Agency warns that some algal blooms are toxic to people and animals. Such harmful blooms are promoted by sunlight, slow-moving water and nutrients such as nitrogen and phosphorus — just the sort of nutrient pollution that often accompanies wastewater discharge.
Bodker also warned of diseases impacting wetland vegetation, such as anthracnose, caused by fungal infection. There’s also the threat of avian botulism — a strain of toxin that’s especially prevalent among waterfowl in North America.
He noted the spores for avian botulism are found just about everywhere. “But they’re not toxic unless they are subject to certain conditions,” he said. “And those conditions are nutrient-rich water, decaying organic matter and warmer temperatures. And those conditions exist because of that sewage right here.”
Hammond has been running the wastewater assimilation system for two years without a current permit under the Louisiana Pollutant Discharge Elimination System, according to DEQ.
In a Feb. 28 email exchange with The Lens, DEQ spokesman Greg Langley described Hammond’s permit as “expired but administratively continued,” meaning the city is still operating the program legally.
“They applied for renewal within [the] appropriate timeframe,” he said.
Langley later noted that there are three other assimilation projects that are “administratively continued”: Guste Island, Terrebonne Parish’s South Wastewater Treatment Plant and the New Orleans Sewerage & Water Board’s East Bank Treatment Plant.
The New Orleans plant was permitted to discharge “a small amount of treated waste water into our wetlands demonstration cells which were constructed several years ago immediately adjacent to the plant on Sewerage & Water Board property, but has never done so,” according to Richard Leidy with Veolia North America, which manages the plant for S&WB.*
These three systems, however, are in the process of being renewed, Langley told The Lens on Wednesday. Hammond’s permit is on hold, pending a comprehensive DEQ review of wastewater assimilation systems across the state. That review, contracted to an environmental consulting firm called Naturally Wallace Consulting, LLC, is due back to DEQ on August 31.
Langley said public concerns expressed to the agency and monthly reports of wastewater discharge, including those from Hammond, prompted a re-evaluation of assimilation projects.
Meantime, DNR is investigating concerns about construction of the discharge pipeline. The Lens obtained a Feb. 18 letter from DNR’s Office of Coastal Management to Comite Resources and the City of Hammond, noting that an enforcement case had been opened “for review of a possible violation of permit conditions.”
DNR noted that the assimilation project’s Coastal Use Permit (CUP) allowed for installation of a “3600 ft. discharge line … to be installed along the south slope of the spoil bank.” But the line that was installed extends 5,525 feet atop the spoil bank, according to the letter.
“The unauthorized clearing for the discharge line installation resulted in approximately 3.52 acres of impacts to Bottomland Hardwood habitat,” the notification continued.
The DNR letter required that the city and Comite respond within 30 days and called for a new permit application to document the unauthorized line installation and clearing activities, as well as “unauthorized pier construction” — apparently referring to long planks of boardwalk running from the area around the discharge pipe towards the edge of the Joyce Wildlife Management Area.
The Lens’ own review of recent discharge monitoring reports, filed by the City of Hammond with DEQ, uncovered a range of violations in the over-10-year period since its own assimilation project came online in 2006, including:
- “metal load” violations involving mercury and copper reported in 2015 and 2016;
- multiple exceedances due to “insufficient aeration & high ammonia levels” reported for the first half of 2016;
- failures of testing for whole effluent toxicity (WET) from August 2015 through July 2016;
- continued failures of tests for WET and exceedances for Biological Oxygen Demand (BOD) in 2017 and 2018, as indicated on LDEQ non compliance reports (linked here, pg 49).
BOD in particular is a frequently cited indicator for the effectiveness of wastewater treatment. It represents how much organic matter is present in wastewater.
As Hammond officials reported the violations, they reported on corrective actions being taken to address them. Many of those actions involved fixing, replacing and adding new aerators at the treatment facility, where they supply oxygen for the biological processes used to break down organics.
“Insufficient aeration and 1 current aerator is in disrepair,” read a May 2018 report on a BOD concentration violation. “Currently awaiting facility improvements. Disrepair aerator has been repaired.”
That same violation report also acknowledged failures to properly test each month for copper and zinc during wastewater treatment. “No copper sample,” it read. “Discrepancy in chain of custody to contract lab caused the samples to go unanalyzed. … A tracking system has been put in place to ensure samples are taken in an accurate timely manner.”
Despite these frequent issues, the Hammond treatment facility continued to pump wastewater in bulk into the wetlands at South Slough.
“During non-rain-event periods, flow is approximately 3.0 [millions of gallons per day],” read a letter to DEQ by the city’s water & sewer superintendent, Guy Palermo — “MGD” stands for millions of gallons per day. “During rain periods, flows have exceeded 16 MGD.”
The Lens asked city officials how rainwater accumulation impacted the facility’s ability to treat wastewater before discharge to the marsh.
“Before heavy rains, we lower the lagoons to compensate,” reads a written response sent by Lacy Landrum, the city’s director of administration. “We have also spent close to $6 million on rehabilitation of our collection system to correct inflow and infiltration problems, and we know this is a primary way stormwater enters the sewer system.”
While heavy rains add more volume to the discharge system, they have something of a benefit in that they dilute the discharge into the wetlands. But they do not reduce the content overall; they reduce the impact of contaminants for each gallon discharged but over time, organic compounds and toxic metals not removed in treatment still enter the discharge area.
To find a defender of assimilation projects, one need look no further than Dr. John Day. He is an emeritus professor of LSU’s Department of Oceanography & Coastal Sciences.
“I have published probably 400 papers that have been peer-reviewed, chapters in books and scientific journals,” Day told The Lens in an interview Monday. “My work has been cited almost 22,000 times, and that’s about 10,000 up from the next person in my department. And I’ve worked all over the world.”
He’s also the founder of Comite Resources — the company that designed Hammond’s assimilation system and continues to monitor Hammond’s system and others across the state.
The City of Hammond said it pays Comite $44,140 a year to monitor discharge and conditions at its sewage marsh. The Secretary of State’s office still lists Day as “officer/director” of Comite and the company’s web site lists him as “president” — but he said he hasn’t been paid by Comite “probably for a couple of years.”
While Day and LSU’s Andree Marie Breaux frequently are credited with development of modern assimilation technique, Day said the practice itself has been used by municipalities for many decades. A 2018 slideshow presentation he produced said the town of Breaux Bridge has been discharging wastewater into the wetlands for 70 years; Ponchatoula, for more than 50 years.
“These things have functioned,” he told The Lens. “Now keep in mind that permitting for these didn’t begin until 1992, with the city of Thibodaux. But it was just plenty of places in Louisiana, opportunistically, just discharged their treated effluent.”
Day said it was only in the late 1940’s that many communities around the country started using a central collection system for wastewater. “Before that, you have individual outhouses or septic systems,” he said. “And it was right after World War II that you get in this massive effort to put in collection systems and bring your effluent, your sewage, to a plant and then treat it and then discharge it.”
Day said wastewater assimilation provides important tertiary treatment for wastewater, after the primary treatment of removing solid waste and the secondary treatment of reducing biological oxygen demand and solids leftover after primary treatment, called total suspended solids.
“What we’ve found is that, [in] every single wetland assimilation system, nutrients are reduced to background levels,” he said. “They aren’t reduced to zero, but they’re reduced to levels that a system has, a wetland has, if nothing [else] was going into it — And that was one of the primary objectives of wetland assimilation.”
Day argued the assimilation technique is poorly understood by its critics, including Bodker. He has written several scientific papers with colleagues at LSU and other schools and his staff at Comite Resources defending the practice and highlighting what he views as abundant evidence of healthy vegetation growth at discharge points, such as South Slough.
“You see several species there,” he said, referencing a photograph of a researcher examining vegetation in the marsh south of the Hammond discharge. “The tall one is cattail, Typha species — this is the end of the growing season when the big seed heads break up and go. But you can see some other species in there — that’s bulltongue or Sagittaria. And then there are some other species down there. So, it’s a fairly diverse community.”
He acknowledged there have been issues with some growth, but he disputes what critics say caused those problems.
In a 2019 article that appeared in the journal Wetlands Ecology and Management, Day, fellow Comite employees Robert Lane and Rachael Hunter, and Southeastern Louisiana University biologist Gary Shaffer rebutted an earlier article by Bodker, LSU professor Eugene Turner and Southeastern Louisiana University biologist Christopher Schulz. Bodker, Turner and Schulz argued that most of 5,000 cypress trees planted about a decade ago near Hammond’s discharge point “either died, floated out of their anchorage, lodged over or manifested signs of abnormal growth.”
For one thing, Day told The Lens, “Most of the trees that died — and we’ve argued about this at meetings — are Chinese tallow,” an invasive species.
He resisted suggestions that treated effluent was to blame for tree deaths in the marsh. He said.
Shaffer, who planted the trees along with his students, determined that shade from tall marsh grasses were a significant factor in the tree deaths.
“You get marsh grass up to about two meters high now,” Day said. “Cypress is very intolerant of low-light conditions. If you plant a cypress tree in your yard, in the shade of a big oak tree, it will either die” or its growth will be stunted.
The trees were planted as part of marsh rebuilding efforts by Shaffer, who frequently has collaborated with Day in assimilation studies.
“We also maintain a nursery of thousands of healthy bald cypress and water tupelo seedlings located adjacent to the discharge pipe and inundated with the effluent,” read the 2019 rebuttal paper by Day and Shaffer.
The Southeastern biologist and his wife, Demetra Kandalepas, have their own environmental consulting firm, Wetland Resources LLC, which promotes cypress and tupelo planting projects to help revive marshland.
When asked if considerations of shade from tall grasses were not taken into consideration when planting the seedlings south of the Hammond discharge, Day said, “Well, we’re learning. No, in retrospect we should have expected it. Seedlings grow very fast but this stuff just took off. And I guess it was unanticipated.”
Day and company place blame for problems with marsh vegetation on nutria, the large invasive rodent species that has earned a name for itself as a disrupter of wetland ecologies.
“There was no evidence of a negative effect on the vegetation until nutria began to impact the area late Fall of 2007,” Day’s 2019 article said. “Intensive nutria removal began in the spring of 2008 and continued through the winter of 2008–2009. Approximately 2000 nutria were killed by shooting. Vegetation recovery began during the Spring of 2009 and was most pronounced and consistent nearest the discharge pipe.”
Bodker cast doubt on the nutria claim. “That’s ridiculous,” he said. “They claim they killed 2,000 nutria, but they don’t have any statistics on it.”
The Lake Pontchartrain Basin Foundation said it had asked Comite for its data on the nutria hunting but received nothing.
“We’re having a hard time pinpointing that that is the sole source for some of the issues that they’re seeing in Hammond,” said LPBF executive director Kristi Trail. “Just knowing that nutria are an issue around the state, if we figured out how to eradicate them in one particular location, we should be using that same process all throughout the state to get rid of them.”
When asked if there was any accounting for time spent hunting the nutria, or daily counts or weight totals of the nutria killed or captured, Day told The Lens, “Actually none, except what we say. There were eight people who participated. I didn’t go out there and do any shooting myself. But just to put this in perspective, again, this was coming at a critical time and the main thing was to go out there.”
Day noted that Shaffer led some of his own Southeastern students onto the boardwalks extending into the marsh to shoot nutria and kept a “rough running tally” of rodents killed.
“If I was to go back and do a lot of things, one of the things is we would have written it all down,” Day told The Lens. “But we didn’t.”
He noted that nutria “eat-outs” have been a common occurrence across the state. “They’ve been occurring ever since they escaped down from New Iberia — you know that story. They bloom up, the females have three litters a year. They’re busy; they could be rabbits.”
Once the nutria run out of marsh to eat, he said, they “die back down and they just quiesce. And these things come and go. And that’s the only thing. You can’t cite another example, anywhere in the world, [with] this concentration of nutria, that causes the wetland to basically crash in a year.”
Trail and Skaggs of the Lake Pontchartrain Basin Foundation note that the science and views on wastewater assimilation have come a long way since the Hammond site was opened for discharge.
“We’re very clear that initially we did support the concept of assimilation in the vein that it may benefit our wetlands, which as we know are in a crisis state,” Trail told The Lens. “However, you fast forward 10 years later, having these sites at practice, we’re not seeing the benefit to it.”
She said she can’t fault the municipalities that use assimilation technique to deal with wastewater, and that these communities cannot simply turn these systems off and immediately switch to something new — alternatives can be expensive to develop and implement.
But there are other costs to consider. One of them is extreme weather.
“From our standpoint, those wetlands are one of our first lines of defense to protect populated areas from storm surge,” Trail said. “If you consider a scenario where you have a hurricane coming in from the east, pushing a bunch of water into the lake, those wetlands there, that are just south of the Hammond-Ponchatoula area, are what absorb that storm surge so that those communities will not flood. You need those there.”
There are also mitigation costs to consider, when such systems damage wetlands.
“We think that, if the true costs were shown, then it would change the way this is done,” Skaggs said. “I think it needs to be the do-no-harm type of strategy. We don’t want to see cutting off our arm at the expense of the rest of the body.”
*Correction: An earlier version of this report incorrectly stated that the New Orleans East Bank Treatment Plant discharges effluent into the Central Wetlands of St. Bernard Parish. That language referred to an experimental project that was never built. “The plant is currently permitted to discharge a small amount of treated waste water into our wetlands demonstration cells which were constructed several years ago immediately adjacent to the plant on Sewerage & Water Board property, but has never done so,” Veolia’s Richard Leidy told The Lens.