Enforcement and Inspection

OIG Says EPA Needs Action Plan for Algal Blooms

The EPA Office of Inspector General (OIG) issued a report on September 29, 2021, stating the EPA is lacking an agencywide strategic action plan to address harmful algal blooms (HAB). The OIG report indicates this has been a serious Agency deficiency since Congress appointed the EPA administrator “as the leader for federal actions focused on reducing, mitigating, and controlling freshwater HABs” under both the Clean Water Act (CWA) and the Safe Drinking Water Act (SDWA).

EPA action plan

HABs are an overgrowth of algae in water, and some produce dangerous toxins in the water. But even nontoxic blooms hurt the environment.

“Harmful algal blooms, dead zones, and fish kills are the results of a process called eutrophication—which begins with the increased load of nutrients to estuaries and coastal waters,” as defined by the National Oceanic and Atmospheric Administration (NOAA).

“Harmful algal blooms impact our nation’s recreational and drinking waters. They occur when, among other conditions, high levels of nutrients—nitrogen and phosphorus—pollute rivers, lakes, and reservoirs,” according to the report.  “These nutrients reach bodies of water from sources such as livestock operations; fertilizer runoff from farm fields, lawns, and gardens; urban stormwater; and industrial and municipal discharges.”

“Nutrient pollution allows cyanobacteria, common in freshwater ecosystems, to grow excessively under certain conditions and form blooms in water bodies,” explains the OIG report. “Some cyanobacterial algal blooms generate cyanotoxins, which are harmful to the health of the environment, animals, and humans. HAB occurrence in sources of drinking water can change the odor and taste of water, and associated cyanotoxins can be harmful to human health if they are not removed during treatment. HABs can sicken people and kill animals; create oxygen-poor zones in rivers and lakes, making them unsuited for aquatic life; raise treatment costs for drinking water; cause economic hardship for industries that depend on clean water; and negatively impact recreational activities. Human exposure to cyanotoxins can result in dermatitis, respiratory illness, gastrointestinal effects, liver and kidney damage, neurotoxicity, paralysis, and death in rare circumstances.”


The OIG report identifies four types of cyanotoxins:

  • Microcystins are the most widespread cyanotoxins and can bioaccumulate in fish, mussels, and zooplankton. Microcystins primarily affect a person’s liver.
  • Cylindrospermopsin is a cyanotoxin produced by a variety of freshwater cyanobacteria. It can damage a person’s liver and kidneys.
  • Saxitoxin effects the nervous system. Exposure occurs through ingestion of untreated drinking water or fish containing saxitoxin in their flesh.
  • Anatoxin-a is a potent neurotoxin that is dangerous to humans and can cause convulsions, respiratory failure, and death in animals.

“Scientists predict that harmful algal bloom occurrences in recreational waters and drinking water sources will increase as excess nutrients continue to flow into water bodies, temperatures warm, and extreme weather events occur due to climate change,” states the OIG report.

Lake Erie has been plagued by HABs for more than a decade. Most recently, Lake Tahoe closed two public beaches due to HABs in October 2021.

In addition to lakes, rivers, and reservoirs, HABs also occur in streams.

An HAB event in Lake Erie in 2014 resulted in more than 400,000 residents losing access to clean drinking water and the city of Toledo, Ohio, investing $400 million in water utilities upgrades.

Water quality standards

As defined by the CWA, water quality standards include:

  • State water quality standards, which include the designated uses and water quality criteria. These standards must provide for the attainment and maintenance of the water quality standards of downstream waters.
  • Designated uses include public water supply; propagation of fish and wildlife; and recreational, agricultural, industrial, and navigational uses.
  • Water quality criteria establish limits on chemicals or conditions in a water body. The criteria protect designated uses; are based on scientific rationale; and can be expressed as acceptable levels or numeric criteria or as narrative statements that describe the desired conditions of a water body, also known as narrative criteria.

CWA authority and tools

Under the CWA, it is unlawful to discharge any pollutant, which includes nutrients, from any point source into navigable U.S. waters without a permit. The permitting process is in place to limit the amount of nutrients entering U.S. waters. According to the CWA, a point source is defined as:

“[A]ny discernible, confined and discrete conveyance, including but not limited to any pipe, ditch, channel, tunnel, conduit, well, discrete fissure, container, rolling stock, concentrated animal feeding operation, or vessel or other floating craft, from which pollutants are or may be discharged. This term does not include agricultural stormwater discharges and return flows from irrigated agriculture.”

The Act also gives the EPA the authority to research the “toxicity of cyanotoxins and the factors driving the formation of HABs, to support regulatory action, as well as to provide guidance, technical assistance, and outreach activities.”

“In 2019, the EPA recommended CWA recreational water quality criteria and swimming advisory values for two cyanotoxins— microcystins and cylindrospermopsin — ‘to better protect Americans’ health when they swim or play near water.’ These recommendations establish concentrations of the two cyanotoxins in water at or below which the EPA determined public health is protected. States may, but are not required, to adopt these criteria and advisory values. The EPA also issued guidance on monitoring cyanobacteria and cyanotoxins in recreational waters and presented risk communication information on its website to help water managers inform people accessing recreational waters about the health risks associated with recreational exposure to cyanotoxins,” according to the OIG report.

SDWA authority and tools

The SDWA gives the EPA the authority to set maximum containment levels for public drinking water systems. The Agency can also issue health advisories for contaminants that do not have established maximum containment levels.

Developed in 1996 as an amendment to the SDWA, the Unregulated Contaminant Monitoring Rule allows the EPA to obtain information about drinking water contaminants that do not have health-based standards set under the SDWA.

“In August 2015, the Drinking Water Protection Act amended SDWA to require that the EPA develop a strategic plan for assessing and managing the risks of cyanotoxins in drinking water, including identifying the steps and timelines to make determinations whether to publish health advisories for cyanotoxins in drinking water provided by public water systems,” the OIG report adds. “The EPA submitted the required strategic plan, titled Algal Toxin Risk Assessment and Management Strategic Plan for Drinking Water, to Congress in November 2015 and committed to develop additional health advisories for cyanotoxins if the EPA found that it had information sufficient for such development, among other actions. The EPA did not establish a milestone for making this determination and has not yet developed additional advisories.”

Harmful Algal Bloom and Hypoxia Research and Control Act (HABHRCA)

The HABHRCA was created in 1998 and established a task force from 11 agencies, including the EPA, “to assess the ecological and economic consequences of HABs; alternatives for reducing, mitigating, and controlling HABs; and the social and economic costs and benefits of such alternatives.”

A 2019 HABHRCA amendment requires the EPA “to determine whether a freshwater HAB event is an event of ‘national significance’ for purposes of mobilizing federal resources to assess and mitigate its detrimental effects, using the following considerations:

• The toxicity of the HAB.

• The potential for the HAB to spread.

• The size of the HAB occurrence.

• The economic impact of the HAB.

• The geographic scope, including the potential to affect several municipalities, to affect more than one state, or to cross an international boundary.

In September 2019, the EPA requested public comment to inform its development of a policy for determining if a HAB event in fresh water is an event of national significance. As of September 2021, the EPA had not finalized that policy.”

OIG recommendations

The OIG recommends that the EPA :

  1. Develop an agencywide strategic action plan that incorporates strategies to:
    • Identify knowledge gaps.
    • Close identified knowledge gaps, particularly related to health risks from exposure to cyanotoxins in drinking water and during recreational activities.
    • Monitor and track HABs.
    • Enhance the EPA’s national leadership role in addressing freshwater algal blooms.
    • Coordinate EPA activities internally and with states.
    • Assess the health risks from exposure to cyanotoxins in drinking water during recreational activities, and establish additional criteria, standards, and advisories, as the scientific information allows.
  2. Publish final numeric water quality criteria recommendations for nitrogen and phosphorus under the CWA for lakes and reservoirs, and publish implementation materials to help states in adopting these criteria recommendations.
  3. Establish a plan, including milestones and identification of resource needs, for developing and publishing those criteria recommendations, although the OIG is mindful that the EPA has substantial work to complete before publishing final numeric water quality criteria recommendations for nitrogen and phosphorus under the CWA for rivers and streams.
  4. Assess and evaluate the available information on human health risks from exposure to cyanotoxins in drinking water and recreational waters to determine whether actions under the SDWA are warranted. Additionally, the OIG recommends that the EPA establish new nutrient numeric water quality criteria recommendations under the CWA in lakes, reservoirs, rivers, and streams and determine whether additional actions under the SDWA are warranted.

“The EPA completed actions to meet one recommendation and provided acceptable corrective actions and estimated completion dates for two other recommendations. The recommendation regarding numeric water quality criteria in rivers and streams remains unresolved.”

Industry takeaways

This action plan, once complete, will impact industries whose activities contribute to higher nutrient levels in drinking water sources.

The OIG report contains a case study on Grand Lake St. Marys in Ohio.

“On January 18, 2011, Ohio designated the Grand Lake St. Marys watershed as distressed,” the report states. “Since that declaration, a variety of watershed-specific rules have been implemented, including a ban on spreading manure on agricultural lands during the winter without prior approval and a requirement that over 130 agricultural producers develop nutrient-management plans. The rules under this distressed designation were phased in to allow time for producers to develop nutrient-management plans and make the management changes needed to comply with the rules, such as constructing manure storage capabilities. In addition, the state and county have completed restoration efforts, including constructing upland and in-lake wetlands and restoring a degraded stream. To date, these nutrient management and restoration efforts appear to be reducing the flow of nutrients to the lake and microcystin levels are moderately declining but are continuing to risk the environment and public health. More time and resources are needed to ensure improved water quality.”