FDEP considers changes to rules for landspreading biosolids

Posted 7/5/19

OKEECHOBEE -- Changes to Florida regulations on the landspreading of biosolids are under consideration. The Florida Department of Environmental Regulation held three public workshops from June 25-27 …

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FDEP considers changes to rules for landspreading biosolids


OKEECHOBEE -- Changes to Florida regulations on the landspreading of biosolids are under consideration. The Florida Department of Environmental Regulation held three public workshops from June 25-27 in Tallahassee, Orlando, and West Palm Beach, respectively.

The draft changes are online at floridadep.gov. The public comment period is open until July 29. Public comments may be made online at floridadep.gov or emailed to Kristin Gousse at Kristin.Gousse@dep.state.fl.us.

The changes under consideration would require annual soil testing of sites where landspreading of biosolids is allowed. Current regulations require testing every 5 years.

The draft language of the rule states that unregulated use, disposal or land application of biosolids “poses a threat to the environment and public health. It is the intent of the department in this chapter to regulate the use, and land application of biosolids so as to ensure protection of the environment and public health including minimizing the migration of nutrients, nitrogen and phosphorus that impair or contribute to the impairment of water bodies.”

Another change under consideration is to remove the exception for septage management facilities that treat 10,000 gallons per day or less on average and no more than 20,000 gallons in a single day.

The rules allow the use of biosolids as agricultural fertilizer, but require annual soil testing to show that fertilizer is needed and a demonstration that the application of biosolids present a low risk of phosphorus transport from leaching and runoff. Each site must have a site-specific Nutrient Management Plan (NMP).

Another change is that “biosolids shall not be applied on soils having a seasonal high ground water table less than 15 centimeters from the soil surface or within 15 centimeters of the intended depth of biosolids placement.”

According to FDEP, Florida produces an estimated 350,000 dry tons of biosolids per year. About 45 percent is processed to the level of Class AA production, which can be sold as fertilizer. About 30 percent is processed to the level of Class B for land application. About 25 percent is disposed in landfills. Additionally, approximately 9,000 dry tons of Class AA biosolids are shipped into Florida from out-of-state facilities annually.

Class AA biosolids are distributed and marketed as fertilizer. Class AA biosolids can be sold or given away under a fertilizer license or to someone with a fertilizer license.

Approximately 39 Florida facilities produce Class AA biosolids with 192,879 dry tons distributed and marketed in Florida and 26,717 dry tons distributed and marketed outside of Florida, according to FDEP.

There are approximately 130 permitted land application sites in Florida for Class B biosolids. Haulers are the most common site permittees. Utilities commonly contract with haulers instead of applying the biosolids themselves.

Under FDEP rules, septage (biosolids pumped from septic tanks) is regulated as biosolids. Since 2016, FDEP has issued 43 septage management facility permits.

Land application permits include: nutrient management plans (NMP); setback provisions; ground water depth provision at the time of application; signage requirements; public access, grazing and harvesting restrictions; runoff provisions; and record keeping/reporting requirements.

The Biosolids Technical Advisory Committee (TAC) convened in September 2018 to evaluate biosolids management and explore opportunities to better protect Florida’s water resources. The TAC members included stakeholders from environmental interests, agriculture, large and small utilities, waste haulers, consultants and academics.

The TAC recommendations include:

• Permit biosolids in a manner that minimizes the migration of nutrients, specifically phosphorus, to prevent impairment to water bodies.

• Establish the rate of phosphorus application based on site specifics, such as soil characteristics, phosphorus absorption capacity, water table, hydrogeology, site use and distance to surface water.

• Increase FDEP inspection rate of land application sites.

• Develop monitoring protocols to detect nutrient migration.

• Develop and conduct biosolid and nutrient management research on nutrient run-off through surface and groundwater flow.

• Promote innovative technology pilot projects for biosolids processing that could provide a wider range of beneficial end products.

At the Jan. 23, 2019 Biosolids Technical Advisory Committee meeting, Dr. Paul Gray Audubon Florida Science Coordinator Everglades Restoration Program, said there is a difference between using biosolids as agricultural fertilizer and the landspreading of biosolids.

Under Best Management Practices (BMPs), farmers test the soil before applying fertilizer and only apply the amount needed for the crop.

Biosolids can benefit agriculture, he said, “but land application primarily is a disposal effort, not BMP compliant, not applied seasonally or specifically.

“If you are growing a crop, you should be fertilizing certain amounts at certain times — that is not how biosolid disposal is happening,” he said.

He also pointed out that the amounts of landspread biosolids are increasing and the locations to dispose of it are decreasing. These recipient locations become liable for other people’s nutrients, Dr. Gray explained.

One dry ton of biosolids per acre provides about 100 pounds of nitrogen and 50 pounds of phosphorus per acre, he said. In 2017, the average loading in the St. Johns River Water Management District was 55 pounds of phosphorus per acre.

The cost to clean excess nutrients out of the water generally ranges from $50 to $150 per pound, Dr. Gray said.

“If the annual statewide Class B land application is 100,000 tons containing 2,200 tons of phosphorus and about 726 tons of available nitrogen, the clean up liability could be in the range of $73-$218 million per year.”

He said the rule that went into effect in 2013 to stop the landspreading of biosolids in sensitive watersheds such as the Lake Okeechobee watershed just moved the problem elsewhere in the state.

Audubon has advocated for Florida to stop the landspreading of biosolids.

Dr. Gray said FDEP set the Total Maximum Daily Load (TMDL) for Lake Okeechobee based on the goal of getting the phosphorus level in the lake down to 40 parts per billion (ppb). He said in the 1970s, when they started testing the lake water, it was around 40 ppb.

To meet that goal, each acre of the 2.6 million acre watershed must average 1/10th of a pound of phosphorus per year. By comparison, the land application rate per acre in the St. Johns River watershed is 550 times that amount of phosphorus.

The video of the Jan. 24 meeting is online at floridadep.gov.

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