Agenda Item Name:
Title
Interlocal Agreement for Landscaping Practices Contaminant Leaching Study with the University of Florida
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Presenter:
Stacie Greco, EPD, 264-6829
Description:
This request is for an interlocal agreement between the County and the University of Florida for a two part study to inform policy recommendations. The first is to quantify the nitrogen leached from lawns treated with synthetic fertilizer, alternative treatments with compost and biosolids based fertilizer, and reclaimed water. The second part is a laboratory and field study to determine the leaching potential of pharmaceuticals, hormones, and PFAS from biosolids based compost products.
Recommended Action:
Recommended Action
Approve and sign the Interlocal Agreement.
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Prior Board Motions:
None.
Fiscal Consideration:
Fiscal Consideration
$97,475 from existing Stormwater Assessment funds.
There is sufficient budget available in the Stormwater Assessment fund 146 to cover the amount needed to complete this study.
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Background:
The County Water Quality Code restricts the application of fertilizer to March through June to reduce nutrient pollution from urban landscapes. Top dressing with compost is a potential alternative to synthetic fertilizer that is gaining popularity. Fertilizers produced from biosolids are an additional source of nutrients which are produced locally. The nitrogen leaching potential of these alternatives is not well established. If these alternatives prove to leach less nitrogen to groundwater than synthetic fertilizer and are not a source of additional contamination, this can inform future changes to the Water Quality Code and outreach programs.
Twelve residential lawn sites will be divided into three groups consisting of a control, a lawn receiving synthetic fertilizer, a lawn top dressed with compost, and a lawn receiving a biosolids based fertilizer. Samples will also be tested for hormones, pharmaceuticals, and PFAS to further our understanding of the potential for leaching these emerging contaminants into groundwater. This study will also evaluate nutrient and contaminant leaching from homes irrigated with reclaimed water and will include a comparison to nearby natural areas.
New landscapes often require significant inputs of fertilizers and irrigation, since the soils are typically low quality. The County is considering modifying the Landscaping Code to require soil amendments, such as compost, to improve soil health in new development. Biosolids is a common feedstock in producing compost products. The second part of this study will be a laboratory column study to measure leaching of hormones, pharmaceuticals, and PFAS over a four week period from various compost products.
UF will manage this project and will utilize collection equipment installed for a previous study that looked at factors contributing to nitrogen leaching from lawns (age, soil type, socio-economic factors, etc.). The previous study was performed for the County by Wood Environmental Solutions with UF as a sub-contractor.