A Natural Resource Management Guide for the County of Morris A ...

Management Considerations
Type and intensity of land use determine quantity and quality of pollutants which are mobilized during rain
events. Table One depicts pollutants, sources and impacts. Residential areas tend to contribute fertilizers,
pesticides, pet droppings, vegetative matter, sediment, litter, debris, household chemicals, and petroleum
hydrocarbons. Commercial and industrial facilities, with vast stretches of impervious surfaces, transmit
petroleum hydrocarbons, nitrates, and heavy metals. Impervious surfaces tend to deliver deteriorating surface
materials, trash debris, thermal loadings, petroleum hydrocarbons, and atmospheric deposits to receiving
water bodies. Pollutants associated with agriculture include sediment, livestock wastes, plant residues,
fertilizers and solid wastes. Construction sites promote sediment-laden runoff which carries many of the
above-listed pollutants.
Common contaminants derived from these sources include nitrogen, phosphorous, carbon, solids, and trace
metals such as lead, zinc, copper and cadmium. Oxygen-demanding substances are responsible for oxygen
depletion in the waterways resulting in fish kills. Trace metals, as well as hydrocarbons, attach themselves
to sediment, settling out over time, and become available for bioaccumulation in plants and aquatic life, often
3
to their detriment. A particular public health concern is lead and its cumulative impact on children. In
addition some petroleum hydrocarbon constituents are carcinogenic. Bacteria, mostly derived from animal
wastes, are usually indicative of other harmful constituents. Trash debris, mainly a visual detraction, is a
forceful instigator in mobilizing citizen action.
Impacts From Natural Hazards
Natural hazards associated with surface water include flooding, erosion, and sedimentation. Erosion and
sedimentation have been discussed in the Soils Chapter. Flooding episodes in the county have been
documented by U.S.Geological Survey. Hydrological data enable us to observe trends occurring throughout
the watersheds. Some discharge records for gaging stations, as well as reservoir volume records, have been
extracted from the 1997 Water Resources Data report and are listed in Appendix C. Notice the fluctuations
of discharge records, and the extreme highs and lows. October 10, 1903 experienced the highest daily mean
of discharge. 1984 followed by 1952 experienced the highest and next highest annual mean discharges,
respectively. 1965 experienced the lowest annual mean.
Extremes can be found from year to year as in a wet 1984 followed by a dry 1985, and
within the same year as in 1996. 1998 presented normal precipitation (as measured at
3 U.S.G.S. index stations) for the first half of the year. From July through December
precipitation rates were far below normal. Records taken at the Passaic River near
Chatham indicated the lowest streamflow levels in seventy-one years of record. At Little
Falls, the Passaic River experienced the lowest streamflow levels in one hundred and two
years of record. 4
3
NJ DEPE, Stormwater and Nonpoint Source Pollution Control Best Management Practices Manual, Dec.
1994, 2.11.
4
US Geological Survey, Water Resources Division. Summary of Monthly Hydrologic Conditions in New
Jersey, Dec. 1998.
A Natural Resource Management Guide
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