harmful algae blooms
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Harmful Algal Blooms

Nutrient Pollution and Harmful Algae Blooms

Many of Rockland County’s waterways are suffering Nutrient Pollution, which is one of the nation’s most widespread and costly environmental and public health challenges (read more on this problem at EPA.gov). Nutrient Pollution occurs when excess nutrients, predominantly Nitrogen and Phosphorus, enter our waterways (see how below) where naturally-occurring algae gobble them up and multiply to high “bloom” levels. Algae blooms can starve the water of oxygen (a condition known as ‘hypoxia’) causing fish and shellfish die-offs. Harmful algae blooms (HABs) can occur in larger receiving waterways, harming health and preventing recreation. Harmful Algae Blooms occur most often during hot weather when too many nutrients are present. These conditions can cause blue-green algae, found naturally in waterbodies, to form toxins that are harmful to humans and animals. Multiple HABs have been confirmed in Rockland County. It can be hard to tell a harmful bloom from a non-harmful one, therefore if you suspect you have seen one or have been in contact with one, please refer and report it to the NYSDEC Harmful Algae Bloom Notification Page. You may also refer to the NYSDEC’s HAB brochure.

Nutrients come from fertilizer, sediment, directing car wash soap to the storm drain, yard clippings, improperly-managed septics, and wastewater treatment plants. Stormwater and our outdoor activities can rapidly carry excess nutrients to storm drains, leaving little opportunity for soil and plants to filter them out. To learn more and to help reduce these impacts, see the CCE Harmful Algae Blooms brochure, our Nutrient Pollution webpage, learn about the Rockland County Fertilizer Law Act, and find out how your everyday activities contribute to Nutrient Pollution. We must always be diligent about our pollutant-generating activities that reach our surface and ground waters!

See the NYSDEC's brochure on Harmful Algae Blooms here: 


harmful algal blooms habs


Jennifer Zunino-Smith
Environmental Resource Educator
(845) 429-7085 x125

Last updated July 8, 2020