The Development of a Nitrogen Control Plan for a Highly Urbanized Tidal Embayment

Abstract

Jamaica Bay is a small (50 km 2 ) tidal embayment located in Queens and Brooklyn, NY in the southwest corner of Long Island. The majority of the bay is part of the Gateway National Recreation Area overseen by the National Park Service. Over the last century the bay has been heavily impacted by man, and as a result suffers from poor water quality. There are two primary reasons for the poor water quality. The first is the four major water pollution control plants (WPCPs), operated by the New York City Department of Environmental Protection (NYCDEP), that discharge approximately 250 million gallons per day (MGD) of secondary treated effluent into the bay. The second reason is man made changes to the geometry of the bay including deep borrow pits used for fill to create the John F. Kennedy International Airport and the creation of islands in the bay, both of which contribute to poor circulation in the back end of the bay called Grassy Bay. As a result of the nitrogen loadings from the WPCPs and the poor circulation in the bay, the bay is highly eutrophic and suffers from high chlorophyll-a concentrations, and periods of hypoxia and unionized ammonia toxicity. The low dissolved oxygen levels violate water quality standards in Jamaica Bay set by the New York State Department of Environmental Conservation (NYSDEC).As part of an order-on-consent with the NYSDEC, the NYCDEP was required to develop a Comprehensive Jamaica Bay Water Quality Plan (CJBWQP) for nitrogen by October 2006 to reduce nitrogen levels in the bay. The reduction of nitrogen levels includes a limit on the nitrogen discharge from the WPCPs to a 12-month rolling average of 45,300 lb/day. The development of the plan included the use of a water quality model to analyze various remediation alternatives. Alternatives included several levels of nitrogen removal at the WPCPs, relocation of the WPCP outfalls, bay recontouring, aeration, and combinations of these alternatives. Costs were developed for each of these scenarios, and cost benefit curves were developed for improvements in dissolved oxygen, chlorophyll, and unionized ammonia.The development of the plan was complicated by several factors, which included multiple jurisdictions with competing interests; public resistance to certain alternatives; possible future water quality standards involving dissolved oxygen, unionized ammonia, and coastal nutrients; the rapid unexplained loss of marshes in the bay; and the fact that the majority of the alternatives would not attain water quality standards 100 percent of the time despite meeting the effluent nitrogen loading limit of 45,300 lb/day. This paper describes the development of this plan.

Large Projected Decline in Dissolved Oxygen in a Eutrophic Estuary Due to Climate Change

“…The biogeochemical model is based on the Row‐Column Aesop (RCA) model, which consists of a water column component (Isleib et al, ) and a sediment diagenesis component (Brady et al, ; Di Toro, ; Testa et al, ). RCA includes two phytoplankton groups, particulate and dissolved forms of organic carbon and nutrients (nitrogen, phosphorus, and silicon), and O 2 .…”

Effects of Wind-Driven Lateral Upwelling on Estuarine Carbonate Chemistry

“…ROMS simulates water level, currents, temperature and salinity. The biogeochemical model is based on the Row-Column Aesop (RCA) model, and includes a watercolumn component (Isleib et al, 2007) and a sediment diagenesis component (Di Toro, 2001). RCA simulates pools of organic and inorganic nutrients, two phytoplankton groups, and dissolved oxygen concentrations (Testa et al, 2014).…”

What drives interannual variability of hypoxia in Chesapeake Bay: Climate forcing versus nutrient loading?

“…The ROMS model was forced by river flows at the heads of tributaries (e.g., Figure b), by sea levels at the open boundary, and by fluxes of momentum and heat across the sea surface. The RCA biogeochemical model has a water column component [ Isleib et al ., ; Zhang and Li , ] as well as a two‐layer sediment diagenesis component [ Di Toro , ; Brady et al ., ; Testa et al ., ]. The model simulates two phytoplankton groups, pools of organic and inorganic nutrients, and both dissolved oxygen concentrations and oxygen equivalents associated with reduced carbon and sulfur [ Testa et al ., ].…”

“…The fourth term ( F vdiff ) represents the vertical diffusive flux across A2 ( K V is the vertical diffusivity). The fifth term (WCR) is water column biogeochemical O 2 uptake in V , and it includes algal and microbial respiration, as well as oxidation of reduced solutes (e.g., NH 4 + and sulfide) [ Isleib et al ., ; Zhang and Li , ]. The sixth term (SOD) is the sediment oxygen demand integrated over the water‐sediment interface (labeled as A3) [ Testa et al ., ].…”