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COVID-19 PLANNING

MITIGATING

HARMFUL

ALGAL BLOOMS

AECOM

Limitations With Some Existing TreatmentsAERATION/OXYGENATIONIncreases the dissolved oxygen levels but does not address phosphorus concentrations. It could potentially exacerbate the situation by aerosolizing cyanotoxins.

GRANULAR PEROXIDEA chemical that oxidizes all organic material in the water column. This will suppress the HAB at the time of application as well as deactivate the potential toxins but it does not remove any of the key nutrients to mitigate future blooms.

COPPER SULFATEAn algaecide that provides temporary relief from a HAB. Lysing the algae cells could exacerbate the issue by releasing cyanotoxins, and adding copper can be toxic to aquatic life.

PHOSPHORUS INACTIVATIONTemporarily suspends HABs from forming by chemical conversion of available phosphorus to limit algae growth. Case studies have shown sediments in most waterbodies are frequently resuspended thereby requiring frequent application.

Harmful Algal Blooms (HABs) are caused by nutrient pollution of water bodies and cost an estimated $1 billion each year in economic damages and losses in the US alone. The US EPA has noted that this is "One of America's most widespread, costly and challenging environmental problems".

HABs containing cyanobacteria (HCBs) can produce toxins that threaten our drinking water supplies and pose serious health risks to humans, livestock, and pets. The most sustainable way to control HCBs is by reducing the supply of nutrients but this approach can take decades to be effective. Immediate action is needed to address the serious human, animal, and ecological health concerns caused by HCBs.

AECOM has led in extensive HAB research and are now complementing that work with mitigation efforts with a focus on full lake and ecological restoration using our patent- pending Hydronucleation Floatation System (HFS).

THE

PROBLEM

AECOM

AECOM’S ALGAE HARVESTING

“NO HARM” SOLUTIONHABITATS Lake Okeechobee, FL (2019)

As part of the USACE-Engineering Research and Design Center (ERDC) Harmful Algae Bloom Interception, Treatment, and Transformation System (HABITATS) research program, AECOM’s Algae Harvesting system demonstrated a viable and scalable “No Harm” solution that can physically remove algae and nutrients from the water and produce an algae feedstock for transformation into biofuel. The demonstration showed greater than 85% removal of total phosphorus, total nitrogen, and chlorophyll-a.

Lake Agawam Demostration Project Southhampton, NY (2019)

The demonstration successfully showcased AECOM’s Algae Harvesting technology was safe and effective in removing algae, nutrients (phosphorus and nitrogen) that fuel algae growth, and microcystin to below EPA guidelines. Test results showed that the algae cells can be safely removed without rupturing.

Average removal efficiencies:• Chlorophyll-a >99%

• Total Microcystin >99%

• Total Nodularin >99%

• Total Phosphorus >90%

• Total Nitrogen >80%

HAB Emergency Clean-upMartin County, FL (2018)

On July 9, 2018, Florida Governor Rick Scott issued Executive Order 18-191, declaring a state of emergency due to the significant areas of HABs in Glades, Hendry, Lee, Martin, Okeechobee, Palm Beach, and St. Lucie Counties. AECOM’s work on this project provided much needed relief to the impacted communities, improving air quality, reducing adverse impacts to the ecosystem , and improving overall quality of life.

HAB Emergency Clean-upLee County, FL (2018)

In response to the state of emergency declared July 9, 2018 in Florida, AECOM provided recovery efforts at 22 locations throughout Lee County. Approximately 400,000 gallons of algae-latent water was transported to the algae treatment plant that generated over 25 tons of biosolid filter cake. Airborne toxins, such as microcystin, endotoxins, and volatile organic compounds, were below exposure guidelines during treatment.

Nutrient Removal Pilot TestLake Bonnet, FL (2017)

Southwest Florida Water Management District (SWFWMD) identified the City of Lakeland as a municipal government in need of support and assistance in mitigating algae blooms that are present in lakes throughout the district. This pilot test showed no toxic effects on vertebrate or invertebrate test organisms. The treatment system successfully removed 81% of the total nitrogen, 82% of total phosphorus, and 92% of chlorophyll-a.

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About AECOM

AECOM is the world’s premier infrastructure firm, delivering professional services throughout the project lifecycle – from planning, design and engineering to consulting and construction management. We partner with our clients in the public and private sectors to solve their most complex challenges and build legacies for generations to come. On projects spanning transportation, buildings, water, governments, energy and the environment, our teams are driven by a common purpose to deliver a better world. AECOM is a Fortune 500 firm with revenue of approximately $20.2 billion during fiscal year 2019. See how we deliver what others can only imagine at aecom.com and @AECOM.

CONTACT

DANIEL J. LEVY, PG

Vice President, Environment,

DCS Americas

305 519 1194

dan.levy@aecom.com

www.aecom.com