What do they do? A decade of questions about Marco’s disabled stormwater inlet filters
Marco Island has been disabling some of its 1,300 stormwater inlet filters for over a decade, according to Public Works Director Tim Pinter.
The filter, when installed with an absorbent material known as a 'hydrocarbon boom,' is designed to capture plastic bags, beer cans, organic solids and oils from stormwater before it reaches local waterways, Pinter said.
"Under previous administration we were basically directed not to purchase more booms," Pinter said during a City Council meeting Feb. 3. "We have not installed (them) for the past three years."
Petroleum hydrocarbons are derived from oil products and some are known to be toxic to aquatic life at low concentrations, according to South Florida Water Management District, a regional governmental agency that manages the water resources in the southern half of the state.
"We have also been directed in the past by an interim city manager not to reinstall some of the filter inlets after we do our maintenance starting before the rainy season," Pinter said.
Pinter says the city also made notches to some inlet structures to increase the water flow coming from swales by bypassing the filters.
"As for the changes to the inlet structures, that was at the direction by previous council and a previous city manager to respond to citizens that were complaining about water standing in their swales," Pinter said.
"Council [...] directed the city manager to have Public Works Department, prior to my [...] directorship, to [...] basically cut notches in these inlet structures to let the flow of water go in and bypass the filters."
Pinter became director of Public Works in June 2010.
David Harden, interim city manager in 2019, directed Public Works to replace the notches, according to Pinter.
"It's not our number one priority but that's something we are doing to allow more water to sit in the swales, to percolate before it goes into the filters," Pinter said
The city began purchasing filter inlets in 2006 and by 2018 it had purchased 834 of them installed by Suntree Technologies for $731,557, according to Pinter. The water district covered these expenses through a series of grants.
"There has been 400 additional inlets installed by various private and public contracts city wide at no direct cost to the city," Pinter said.
In 2005, the Waterways Advisory Committee petitioned City Council to go evaluate a process to remove debris and other materials from stormwater before it reaches canal waterways, according to Pinter. In 2006, the city requested a bid for storm water inlet treatment systems.
"The system would consist of filter material to capture hydrocarbons, grease and oils and screens of various sizes to capture debris without compromising the ability of the stormwater management system to handle large volumes of water," Pinter said.
After the bid was advertised, the city received six bidders with three different types of inlets, Pinter said. After discussions during two meetings, City Council decided on Feb. 6, 2006 to award the contract to Suntree.
Polluted stormwater runoff is commonly transported through municipal separate storm sewer systems or MS4s, and then often discharged, untreated, into local water bodies, according to the U.S. Environmental Protection Agency's website.
To prevent harmful pollutants from being washed or dumped into MS4s, certain operators like the city of Marco Island are required to obtain a National Pollutant Discharge Elimination System or NPDES permit and develop a stormwater management programs or SWMP.
The SWMP describes the stormwater control practices that will be implemented consistent with permit requirements to minimize the discharge of pollutants from the sewer system.
Florida Department of Environmental Protection is authorized by the EPA to issue permits to regulate discharges to surface waters, according to Alexandra Kuchta, DEP's operations analyst.
"NPDES permits include requirements that are tailored to the specific operations of the facility, require compliance with surface water quality standards and establish stringent monitoring requirements to ensure these standards are met," Kuchta wrote in an email on Feb. 14.
During the City Council meeting on Feb. 3, City Councilor Sam Young spoke negatively about the Suntree filters.
"I personally went out [...], pulled off the crates and the water was missing these things entirely," Young said. "It was all collected at the bottom of the junction box."
"So this is misleading at best."
"Some of these things are so poorly made that they are already falling apart and pretty soon, when they disintegrate, they are going to be obstructions," Young said.
Pinter said the filter systems were not falling apart.
"They are stainless steel, they are fiberglass," Pinter said. "They are not degrading."
"I can tell you right now, the statement that the filters are incorrect and they are degrading is false."
This was not the first time Young spoke publicly about the Suntree filters.
On April 29 of last year, Young said during a workshop the filters were not properly installed and that many concrete boxes were too large for them.
“It’s impeding water flow, serves no value and is a waste of money," Young said.
On Jan. 13, City Council unanimously passed a resolution approving a site development plan amendment for Marco Town Center despite their plans to install Suntree filters.
At that meeting, Young said the city's Suntree filters were installed incorrectly.
"And they don't work," Young said. "Why would you go to Suntree filters?"
Suntree Technologies denied it incorrectly installed the filters in Marco Island.
"Suntree denies the allegations laid out by Councilman Young," Jake Jacobson of Oldcastle Infrastructure, a partner company of Suntree Technologies, wrote in an email on Feb. 14.
"Around 2006, the City of Marco Island approached Suntree to provide catch basin filters," Jacobson wrote. "Thereafter, the city provided Suntree with the specific measurements it needed for each filter, and Suntree manufactured all filters to those specifications."
The city approved the filters before they were installed, according to Jacobson.
"Any alleged issue relating to the filters would be the result of improper maintenance, not the manufacture of the product," Jacobson wrote.
The water district, within its best management practices, said in 2002 the pollutant-removal effectiveness of water quality inlets like the ones used by the city are limited.
"The devices should be used only when coupled with extensive clean-out methods," according to the document. "Maintenance must include proper disposal of trapped coarse-grained sediments and hydrocarbons."
"Clean-out and disposal costs may be significant."
The city cleans out the filters once a year, according to Pinter, but the Suntree filter manual recommends they should be serviced quarterly.
In 2016, the city cleaned all 1,324 filter inlets and recorded 13,599 pounds of debris removal, according to Pinter. The city recorded 8,000 pounds in 2017 and a city contractor recorded 13,560 pounds in 2018.
Despite these results, Young said the filters had not improved the quality of the local waterways.
"If the point was to improve our water quality, it failed," Young said.
Pinter said at the City Council meeting there has been 'a lot of misinformation' in Marco Island about the Suntree filters.
"It was never intended to reduce nitrogen or phosphorus in the system," Pinter said. "It was to collect debris and it was to filter hydrocarbons and other items that were produced off of roadways, in parking lots and in swale systems."
Nitrogen and phosphorus are the principal nutrients of concern in urban stormwater, according to the water district.
"In excess, they increase primary biological productivity and may cause unwanted and uncontrolled growth of algae and undesirable aquatic weeds," according to the water district's best management practices.
"The major sources of nutrients in stormwater are urban landscape runoff (fertilizers, detergents, and plant debris), atmospheric deposition, and improperly functioning septic tanks."
City manager Mike McNees said a number of the inlet filters were disabled.
"I think what's pretty clear here is there are a number of these are not functioning as they are supposed to because they were disabled," McNees said at the City Council meeting on Feb. 3. "They were modified so that they wouldn't work, so that individual swales wouldn't flood.
"We know that. [...] We know it's true, some of these were disabled. We know it's true and many of them don't have these booms to take the hydrocarbons out of the water because they weren't being funded anymore."
McNees said one option is to remove all 1,300 plus filters.
"If it is a widely held opinion among the council members that they are a waste of money because of what they are intended to do isn't worth doing, we can stop," McNees said. "We can take them out, we can stop maintaining them, we can stop cleaning them and we can just vacuum catch basins once a year."
"What staff is telling you is the removal of the plastic bags, the removal of the cans, the removal of the things they do take out is worthwhile and we believe that's why [...] the water management district paid for them in the first place, they believe there is value there."
After the discussion, City Council directed McNees to do an evaluation of the cost-benefit of the Suntree filters and to come back with recommendations.
On Aug. 22 of last year, the Department of Environmental Protection put the city on notice that its waterways were impaired and in need of a corrective plan after Young asked the state to officially acknowledge the city's water quality issues.
"The department has recently completed its evaluation of available water quality data and has determined that several waterbody segments do not meet nutrient water quality standards," water quality assessment program administrator Jennifer Espy wrote.
Excessive nutrient supply can stimulate the growth of nuisance plants, creating, on occasion, algal blooms, according to a 2019 study on nitrogen levels in Marco waters. Algal blooms can reduce water clarity and impact corals and sea grasses that provide food and shelter for fishes, crabs and shrimp.
"Once algal blooms die-off, their decomposition can reduce levels of dissolved oxygen, which is essential to most forms of aquatic life," according to the report.
The report concluded nitrogen levels have increased within Marco waterways over the past four years and over the past five years within the waters surrounding the island.
"The waterways via tidal exchange may already be problematic before it enters the canals," according to the report. "Finding ways to reduce the upland sources of nitrogen, coupled with increasing the time it takes storm water to enter the canal system would help reduce the nitrogen loading coming from the Island land uses."
In case you missed it:City Council awards contract to evaluate source of nutrients in Marco waters
For these services, the city agreed to pay an amount not to exceed $131,065.16, according to city documents.
The contract only covers phase one of the project, said Lina Upham, purchasing and risk manager.
"This process will take approximately one calendar year spanning between fiscal year 20 and fiscal year 21," Upham said during a City Council meeting on Jan. 6. "This award contract is for phase one because this is an operating expense."
"We had to split it between fiscal 20 and 21 because we legally cannot obligate the funds for 21."
The project will include monitoring of open waters, not just canals, said Harvey H. Harper, project director and founder of Environmental Research & Design (ERD).
"They (city staff) wanted to continue to use the data collected by the county and our monitoring will supplement that," Harper said on Jan. 6. "So, if they are monitoring mostly in the canals then we will be monitoring elsewhere in the open water."
ERD will also analyze historical water quality data, according to the contract.
A final report, which is part of the second phase, will be completed by summer of 2021, according to exhibit C of the contract.
Omar Rodríguez Ortiz is a community reporter for Naples Daily News and Marco Eagle. Follow him on Twitter and Instagram as @Omar_fromPR, and on Facebook. Support his work by subscribing to Naples Daily News.