Nutrient management from coast to coast
Across the country, many states are dealing with similar environmental issues. This month, thanks to funding from the EPA’s National Estuary Program Grant, we invited experts from Long Island Sound, Chesapeake Bay and the San Francisco Bay to speak to the Puget Sound Nutrient Forum and share their work on reducing nutrients in estuaries. Puget Sound is the country’s second largest estuary, an area where saltwater from the ocean meets freshwater from rivers. Our state shares similar challenges as other coastal estuary states.
Many coastal areas need to reduce the amount of nutrients coming into the waterway. Excess nutrients can come from humans and cause low dissolved oxygen conditions, a problem for aquatic species and food webs. Long Island Sound and Chesapeake Bay were experiencing extremely low levels of oxygen, called hypoxia, due to excess nutrients from humans. Through state-run clean-up plans, each state was able to reduce human nutrient sources and improve water quality.
There’s nothing like a good success story to keep us inspired in our nutrient reduction strategies. Check out some highlights from their work:
Tricks of the trade from Long Island Sound
The Long Island Sound’s largest source of nutrients, according to Rowland Denny of the Connecticut Department of Energy and Environmental Protection, was discharges from wastewater treatment plants (WWTPs). Connecticut’s cleanup plan focused solely on reducing nutrients at WWTPs.
Because treatment technologies can be costly and require long-term planning, Connecticut set out to create a cost-effective plan in the 1990’s to restore a healthy Long Island Sound.
To start their cleanup plan, Connecticut first established a cleanup goal: reduce nutrients from WWTPs by 58.5%. Their plan has three main elements:
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Changes in hypoxia in Long Island Sound from 1994-2018.
Extreme hypoxia (red) is entirely gone and the Sound
is much healthier.
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- Require equal nutrient reductions at WWTPs: This means all WWTPs in Connecticut were given the same minimum nutrient reduction requirement and were on the same compliance schedule.
- Give the WWTPs time to transition: Requirements ramped up in three stages: a first reduction goal by 2004, a second reduction by 2009, and finally the total 58.5% reduction by 2014. This gave WWTPs time to make strategic upgrades to their facilities
- Allow trading: If WWTPs reduce nutrients beyond the requirement, they can sell excess “credits” to WWTPs unable to meet their requirement that year. The state manages the trading program providing a financial incentive to reduce more nutrients than required. It also gives flexibility for WWTPs to buy credits when they have difficulty meeting their requirement. Total nutrients from all WWTPs that enter the Sound must meet the reduction requirement, ensuring the Sound is still healthy even if a few WWTPs don’t meet their exact targets.
Result: Success! Long Island Sound was able to meet required reductions by the 2014 deadline. The plan was cost-effective and flexible for WWTP treatment upgrades, and 61 facilities upgraded their treatment technologies.
For more info, visit the Long Island Sound Nitrogen Trading Program webpage.
Chesapeake Bay: the grass is greener
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Allan Brockenbrough, Virginia Department of Environmental
Quality, speaking at the Puget Sound Nutrient Forum.
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To clean up the Chesapeake Bay, Allan Brockenbrough from Virginia Department of Environmental Quality, explained the need to reduce nutrients from all human sources to meet their bay cleanup goals. Allan described Virginia’s nutrient management plan as “everyone doing everything, everywhere.” The most significant source of nutrients to the Bay was WWTPs, but other human sources were also quite high, including agriculture, runoff from urban areas, forestry, and septic systems.
Similar to the Long Island Sound cleanup, Chesapeake Bay used a nitrogen reduction requirement for WWTPs and allowed trading. They also created technology requirements so that any new facilities or planned upgrades must meet minimum reductions set by the cleanup plan.
Virginia included reduction for non-point sources, or sources that don’t directly discharge into the Bay. This includes fertilizer run-off from agriculture, stormwater pollution, and failing septic systems. Virginia allowed non-point sources that met nutrient reduction goals to trade with WWTPs. They also did outreach to involve all residents in cleaning up the Bay.
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Recovered eelgrass provides habitat for the famous
Chesapeake Bay Blue Crab.
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Result: Success! Chesapeake Bay is on its way to meeting the nutrient reduction goal and you can literally see the improvements. Eelgrass and other aquatic vegetation is recovering and providing habitat for fish and aquatic species. Eelgrass also protects shorelines by lessening wave impact and keeping water clear by rooting down seafloor sediment.
For more info, visit the Chesapeake Bay water cleanup plan webpage.
San Francisco Bay: Same, same, but different
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San Francisco Bay, seen here, is also concerned about
a growing human population.
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Our West Coast estuary neighbor, San Francisco Bay, is planning for future population growth and climate change impacts on their waterways. Nutrient issues have been kept at bay here, due to the strong tides. But, there are concerns about the effects of algal blooms from excess nutrients.
David Senn, from the San Francisco Estuary Institute, explained that just because excess nutrients aren’t obvious now, it doesn’t mean it won’t be an issue as the human population grows in the surrounding area. That’s why San Francisco wastewater treatment plants and other stakeholders are investing in monitoring and science.
Puget Sound is also a quickly growing region and is not immune to the impacts of climate change. That’s why we use our sharpest tool in the (water)shed, the Salish Sea Model, to help us understand the impacts of future growth and climate change on the health of Puget Sound. You can explore our recent modeling results evaluating nutrient reductions in Puget Sound on our Salish Sea Model webmap.
Sharing is Caring
We plan to stay connected with other nutrient management plans around the U.S., because we all benefit from each other’s successes and lessons learned. Managing excess nutrients is a global issue, especially in coastal estuaries near growing populations.
If you’re interested in what’s being done to reduce nutrients in Puget Sound, please visit our project page for resources and to sign up for email updates. All Forum meetings are open to the public.
Funding for guest speakers’ travel to the Puget Sound Forum was provided by the EPA’s National Estuary Program.
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