Water Quality

What is Nutrient Pollution?

Nutrients, like nitrogen and phosphorus, are naturally occurring – but can be too much of a good thing when found in high concentrations in our waterways. These nutrients are very high in sewage, septic tanks, storm-water runoff, and fertilizers.

Nutrient pollution can contribute to algae blooms. Algae blooms turn the water green and smell terrible, smothering seagrass and killing fish -- they can even be harmful to humans.

Potential Sources of Nutrient Pollution


Fertilizer is often over-used in residential landscaping. Biscayne Bay and our canals are extremely sensitive to excess nutrients, so we have to be sure to keep these nutrients out of the water to avoid algae blooms.

Septic Tanks

When not properly cared for, septic tanks can leak or flood – creating a land-based source of pollution that drains into our waterways. This pollution can also contaminate the aquifer, our drinking water stored underground. Always maintain your septic tank and have it regularly inspected.

Storm-Water Runoff

Storm-water Runoff is any type of water that doesn’t soak into the ground, but instead “runs off” down a drain or grate and into a waterway. Sometimes this water flows over polluted areas such as parking lots, roads, industrial sites, or yards, bringing contamination into waterways.

Tips to Reduce Nutrient Runoff Pollution

  • Minimize or eliminate fertilizer, herbicide and pesticide use—or switch to organic varieties that are not harmful
  • Plant native plants – they are naturally adapted to our climate and don’t require a lot of water and fertilizer
  • Avoid over-watering your lawn 
  • Use mulch instead of herbicides to help control weeds
  • Sweep up debris – don’t hose down your driveway
  • Minimize or eliminate fertilizing in the summer months when rains are heavy
  • Have septic systems inspected and pumped out every 3 years
  • Routinely check your car for leaks and dispose of engine fluids properly
  • When washing your car at home, use detergents sparingly or bring your vehicle to a commercial car wash
  • Pick up trash, pet waste and litter around your yard and home

Additional Resources

Stormwater Runoff Brochure Cover English.jpg Stormwater Runoff Brochure Cover Spanish.jpg
Storm Water/Nutrient Runoff Brochure English Storm Water/Nutrient Runoff Brochure Spanish