Agricultural Output

• Monoculture encourages growth of pests
• Broad use of chemical pesticides
• Highly mechanized farms, large acreages, big mortgages
• Feedlots for fattening cattle; animal factories
• Genetically engineered crops

• Fertilizers (runoff leads to eutrophication of waterways)
• Insecticides, herbicides, fungicides, rodenticides
• Manure disposal; runoff rich in nitrogen (e.g., poultry and hog farms)
• Overuse of water in desert areas

• Chemicals (natural/synthetic; biodegradable/non-biodegradable)
• Thermal loading (associated with electrical generating facilities)
• Sewage contamination (pathogens, nutrients, toxics)
• Eutrophication (overabundance of nutrients in a waterway)
• Biological Agents (exotic and invasive species; infectious agents)
• Salts (salination)
• Erosion and sedimentation
• Point and Non-point Source pollution
• Point Sources include sewers, industrial discharges, street drains, combined sewer outfalls
• Non-point Sources include stormwater runoff, agricultural runoff, road runoff, ISDS units, landfill drainage, erosion & sedimentation processes

• Centralized treatment plant combined with sewer lines (POTW)
• Areawide collection system (sewers)
• Usually municipal or county operation
• Comprised of primary (settling tanks), secondary (aeration), & tertiary treatment (sand filtration)
• Expensive to build and maintain
• ISDS (on-site treatment; common in rural and suburban areas)
• Components: septic tank, leach field, sometimes a denitrification unit
• Effectiveness dependent on soils, slope, age, usage
• Recommended 2-acre zoning (1 building/2 acres)
• Major source of non-point source pollution
• Chemical or biological processing
• Bioactive system based on degradation by microbial organisms (may be aerobic or anaerobic degradation)
• Composting toilets (widely used in Scandinavia & other parts of Europe)

• High organic content; most contamination in first few hours of storm
• Contains auto pollutants, pet wastes, waste oil, industrial pavement runoff
• May have toxic components (as much BOD loading as household sewage)
• Combined sewers in old cities (mix sanitary sewage with street runoff); called CSO

• Thermal Effluents (heated water from electrical power plants and industries)
• Toxic Chemicals (e.g., treatment lagoons, injection wells, groundwater contamination)
• Industrial Discharges (require an NPDES permit - National Pollution Discharge Elimination Permit, according to Clean Water Act)

• BOD (Biochemical Oxygen Demand) and DO (Dissolved Oxygen)
• Nitrates (NO3) and Phosphates (PO4) - act as fertilizers, cause eutrophication
• Salinity and Chlorinity (test for salts)
• Light transmittance
• Conductivity (indirect measure of dissolved substances in water)
• Coliforms (measure of bacteria common to sewage)
• Specific chemicals (including inorganic chemicals like Hg, Pb, Cd; and organic chemicals like petroleum HCNs, VOCs, PCBs, etc.)

• Clean Water Act
• Original passage - 1970; amended many times, approximately every 7 years
• Contains provisions for Water Quality Standards, NPDES Permits, Sewer Construction Grants, Sect. 208 Public Participation, Rivershed Planning
• Initial focus on point source pollution; later on non-point source pollution
• Safe Drinking Water Act (focus on drinking water quality & protection)
• RCRA (Resource Conservation & Recovery Act) - focus on managing solid wastes
• TOSCA (Toxic Substances Control Act) - focus on preventing exposure to toxics
• State Laws (wetlands protection, aquifer management; drinking water quality and quantity)

• Natural drainage sites (absorb flood waters, prevent erosion)
• Swamps, marshes, bogs, and estuaries (associated with ponds, lakes, streams, rivers and coastal areas)
• State laws and agencies provide greatest protection
• Important habitat areas; characterized by high biodiversity
• Protection of "vernal pools" in Massachusetts and Rhode Island
• Wetlands often protect underground aquifers (via groundwater recharge zones)

• Source of inspiration for poets and writers (see Rivers Project)
• Need to be better protected, especially "wild rivers"
• Linked to population centers (often used for waste disposal)
• Mixed use areas (uses may be in conflict); Riparian rights
• Often subject to flooding (use of 100-Year Floodplain concept)
• Best managed by watershed approach

• Linkage of drinking water and sewage (rates are connected as well)
• Quality issues (aquifers & reservoirs, drinking water quality criteria)
• Quantity issues (aquifer recharge, drought effects, overconsumption, long range planning)
• Cost savings associated with conservation (water purchase, electricity for pumping and heating, sewage treatment, supply management)
• Water conservation technology (low-flow toilets, showers and faucets)