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NY/NJ Harbor Nutrient TMDLs Update |
Robin Landeck Miller, John P. St. John, and James R. Wands |
| Abstract:
The New York/New Jersey Harbor Estuary is one of twenty-eight estuaries of national significance in the National Estuary Programs created by Congress in 1987 under Section 320 of the Clean Water Act. For more than a decade, the NY/NJ Harbor Estuary Program (HEP) and the States of New York and New Jersey have been working toward developing TMDLs for nutrients to attain dissolved oxygen standards in HEP waters as called for in the Comprehensive Conservation and Management Plan (CCMP). The permitted dischargers to the NY/NJ Harbor estuary have been important stakeholders in the TMDL process. The TMDL process for the Harbor involves both measured data and numerical models. The permitted dischargers have been instrumental in voluntarily and pro-actively funding the model development and data collection efforts. Model applications to date, led by EPA and the States, have shown that both carbon and nitrogen loadings contribute to non-attainment of water quality standards throughout various subregions of the Harbor. Early results indicate that, for the majority of the Harbor, fairly robust reductions of both nitrogen and carbon from both point and non-point sources may be required to attain or approach attainment of water quality criteria and standards for dissolved oxygen. Accordingly, a more targeted analysis, at the subregional or management zone scale, is being undertaken to further pinpoint specific loading reductions and management actions that may be required for nutrient TMDL/WLA/LA purposes. The targeted loading reduction analysis will involve conducting modeling scenarios using the System Wide Eutrophication Model (SWEM). It is noted that many of the permitted point source dischargers to the Harbor in New York and New Jersey are undertaking a costing analysis. It is intended that the point source nitrogen and carbon treatment upgrades for which costs are developed by the dischargers will be complementary to the loading reductions considered in the model scenarios. The model will provide the receiving water dissolved oxygen improvements associated with the loading reductions. Cost-benefit curves will be constructed to identify those specific loading reductions that are most cost-effective in terms of improving receiving water dissolved oxygen. A knee-of-the-curve approach is planned. |
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