We all can take actions to contribute to cleaner water! The toxic red tide and blue-green algae that have been plaguing Florida’s coastal economies and ecosystems are fed by nitrogen and phosphorus nutrients. These nutrients fuel the toxic algae blooms and are typically associated with fertilizer carried in stormwater or irrigation runoff and treated wastewater. This paper provides an overview of strategies to reduce this nutrient fuel at the individual/building, neighborhood, and watershed/regional scales.
So what can an individual do? The key is to reduce both the application of fertilizer rich in nutrients to landscapes as well as runoff from landscape irrigation and rainwater. The following strategies are recommended:
Build healthy soil in your yard by increasing its organic content using compost, manure, and biochar. Such soils will hold more water, nutrients, and microbes for use by landscapes. This first-line, front-line strategy can reduce or alleviate the need for fertilizer as well as reduce irrigation by increasing drought resistance and deeper and more efficient root zones.
Use native or Florida Friendly landscape vegetation to reduce artificial irrigation demands.
If an in-ground irrigation system is installed, use efficient irrigation strategies such as micro-jet irrigation, limited turf, plant groupings, and control via soil moisture sensors.
Reduce stormwater runoff from impervious surfaces with such strategies as pervious pavers, and rainwater cisterns. Rainwater captured in cisterns from roofs can be used for help meet outdoor non-potable irrigation or even indoor potable water demands depending on the level of treatment and/or plumping accommodations.
Whether you are on central water and sewer or well and onsite wastewater disposal system, use indoor water plumbing fixtures with the WaterSense label to reduce wastewater loads.
If you use on an onsite wastewater disposal system, consider the placement of a passive nitrogen reduction media under the drainfield for denitrification (http://www.floridahealth.gov/environmental-health/onsite-sewage/research/finalnitrogenlegislativereportsmall.pdf).
Scaling up to the neighborhood scale can be a bit more challenging in that it may require the retrofit of existing built systems or renegotiation of existing contracts. However, neighborhood associations and residents may collectively provide an environment that is friendly to the implementation of the building scale strategies. In addition, the following strategies are recommended:
Use water from existing stormwater ponds as a means to recycle nutrients (and stormwater discharges) to meet community irrigation demands.
If your community uses reclaimed water for irrigation, negotiate that it be treated to Advanced Wastewater Treatment (AWT) which establishes and requires that nitrogen and phosphorus nutrient concentrations are capped.
Build healthy soil in your common areas by increasing its organic content using compost, manure, and biochar. Promote soil building at the building scale.
Establish a community composting operation in a common area or the nearest public park. Stormwater ponds by design are intended to collect nutrients from neighborhood runoff and reduce them prior to discharge to the public waterways and estuaries. These collected nutrients can also fuel the growth of non-toxic algae in the stormwater pond. Management of this algae and the nutrients that fuel them is a management issues that is common to most communities. There are emerging strategies that could passively adsorb these nutrients and non-toxic algae that could then be recycled in a compost operation or as a soil amendment that would also help reduce the need for fertilizer.
Promote native or Florida Friendly landscape vegetation in common areas to reduce artificial irrigation demands.
If an in-ground irrigation system is installed in common areas, use efficient irrigation strategies such as micro-jet irrigation, limited turf, plant groupings, and control via soil moisture sensors.
The building and neighborhood scales have the advantage of providing for effective nutrient management at the source as well as not being dependent on public or government investment. On the other hand, since the governmental agencies are typically charged with managing the receiving water bodies – lakes, streams, rivers, estuaries, and bays as a public resource. In addition, governmental agencies are typically responsible for providing central water and wastewater service. In this context, the following strategies are recommended at the watershed or regional scale:
Work with residents and communities to promote and incentivize strategies at the individual building and neighborhood scales.
If treated reclaimed wastewater is to be reintroduced into the environment including for irrigation, meet Advanced Wastewater Treatment (AWT) standards to manage nitrogen and phosphorus nutrient concentrations.
Invest in a water quality monitoring program to determine increasing or decreasing nutrient trends.
Invest in a rainfall and water quantity monitoring program to determine seasonal and annual water budgets as basis for hydrologic and watershed restoration.
Invest in the development nutrient – nitrogen and phosphorus - budgets for various land uses.
Invest in hydrologic and watershed restoration projects to restore a more natural nutrient and hydrologic water budget to receiving waters.
Invest in research and pilot projects that can be applied at the individual/building, neighborhood, and watershed/regional scales to reduce or mitigate fertilizer and water use.