Water Quality

Pollutant Loading Model

2004

The template for this model was developed by the Center for Watershed Protection (CWP). Input summaries for the Bronx River CSO's were prepared by NRG staff.

Pollutant loading rates were generated for the five CSO areas (HP-004, HP-007, HP-008, HP-009, HP-010) that drain to the Bronx River. Combined sewers HP-008 and HP-010 do not overflow due to the ability of the combined sewer system to handle both small and large storm events without discharging to the river.

To read more about this model, download a PDF of the Pollution Loading Model Summary (146 KB).

Bronx County CSO Drainage Areas

Bronx River CSO sheds in Bronx County

Land Use Statistics

CSO	Total Area (Acres)	Impervious Area (Acres)	% Impervious
HP-004	506	418	82.70%
HP-007	1314	1036	75.10%
HP-008	211	161	76.60%
HP-009	403	285	70.90%
HP-010	218	78	36.10%

Combined Sewer Outfall area and impervious area calculations generated from EMERGE data.

Summary of Loading Rates

A breakdown of loading rates by source for each CSO is given in Appendix 1 of the Pollution Loading Model Summary (PDF, 146KB).

CSO	Area (acres)	Impervious (%)	TN (lb/yr)	TP (lb/yr)	TSS (lb/yr)	FCOL (billion/yr)
HP-004	516	82.7	4,996	694	246,250	781,190
HP-007	1,305	75.1	12,617	1,704	636,700	1,785,689
HP-008	213	76.6	1,955	267	102,950	130,329
HP-009	404	70.9	3,856	519	198,015	744,834
HP-010	144	36.1	1,086	146	70,650	86,758

Summary of pollutant loading (TN - total nitrogen, TP - total phosphorus, TSS - total suspended solids, FCOL - fecal coliform) from each combined sewer outfall draining to the Bronx River.

Methods

Land use data was obtained through the PLUTO system, a GIS database comprised of land use and infrastructure data developed by the New York City Planning Department.

A fine resolution (3 x 3 ft.) land cover data set was used to calculate impervious, grass, and tree cover statistics within these land uses. This EMERGE layer was generated by the USDA Forest Service. The raster data set is classified by cover type (tree, grass, impervious surface, or unclassified). Further descriptions of these classifications can be found in Myeong, 2001.

Other GIS data layers including road networks, watershed/sewershed delineation, and orthophotography were acquired from the NYC DPR GIS database.