Module 3.2 Pollution Prevention

Transcription

1 Module 3.2 Pollution Prevention Prevention of Water Pollution from Nonpoint Sources A nonpoint source is a location without an identifiable point of discharge to a water body Important nonpoint sources include: Agricultural facilities: feedlots, farms, Construction sites Development of urban and suburban areas close to streams, rivers, lakes or the ocean Parking lots Nonpoint sources of water pollution are addressed in the: The Clean Water Act (CWA) There is no permitting process for nonpoint sources of pollution Conservation of water use may be important here but, more often, it s precipitation and runoff that are the problem Rain and snowmelt pick up pollutants and carry them to surface or groundwater Rain and snow runoff cause erosion and carry sediment into surface water bodies Nonpoint sources are addressed through a process involving: Best management practices (BMPs) Initially using BMPs was voluntary but increasingly they are required in order to get permits to carry out construction activities, operate facilities, develop areas, etc. 1

2 Both large and small agricultural operations handle materials and pose a risk to the quality of surface and groundwater Fertilizers Pesticides Oil, gas, and other mechanical fluids Manure Erosion of soil leading to increased sediments in streams Other If not handled properly, these materials can contaminate water supplies through: Improper application (application followed by runoff to surface water) Spills and leaks Infiltration to the groundwater Historically: Agricultural operations were small Population density in rural areas was low Synthetic pesticides and fertilizers were rare Feedlot operations were small, numbering in the 100s or 1000s of animals Manure was spread as a natural fertilizer Now: Many agricultural operations are very large, in fact, industrial agriculture is common Urban and suburban growth has infiltrated rural areas Synthetic pesticides and fertilizers are common and heavily used 2

3 Feedlot operations are often large, numbering in the 10,000s or more animals Manure is a serious issue for odor, gas generation, and the potential to spill to surface water or infiltrate to groundwater Large feedlot operations also have a real problem with disposal of animal carcasses Collection ponds for manure Buffer strips around fields to protect streams Grass waterways to reduce erosion of soil and increased sediment in streams No till farming, no fall plowing, contour plowing Good housekeeping and careful handling of pesticides and fertilizers Timed application of only the amount of fertilizer and pesticide needed Participation in the conservation reserve program Construction Because construction activities disturb the ground, they can be a source of serious pollution of surface water, at least in the short term The construction industry is a leader in the development and implementation of best management practices to control runoff Construction Examples include: Setting up erosion control barriers where water is likely to run to slow flow, catch sediment, divert runoff, etc. Use of biofabrics and other physical barriers on top of bare or disturbed ground to minimize erosion Fast revegetation including hydroseeding, replanting of grasses and shrubs, native vegetation Water spraying on bare dirt roads to minimize dust from vehicles Good housekeeping related to maintenance of, and fluid handling around, equipment 3

4 Development of New Areas One way to manage the implementation of BMPs is to require their use in newly developed urban and suburban areas Often you can see the best examples if you visit a new subdivision or newly constructed commercial park Examples: Retention basins to hold water runoff until it can infiltrate into the ground Mandated grassy areas to allow infiltration, not everything should be paved Vegetated buffer zones between developed areas and streams, rivers, and lakes Traditionally, BMPs have focused on good housekeeping measures and good management techniques intending to avoid contact between pollutants and water media as a result of leaks, spills, and improper waste disposal. However, BMPs may include the universe of pollution prevention encompassing production modifications operational changes materials substitution materials and water conservation and other measures. General BMPs are applicable to a wide range of industrial operations Good housekeeping to keep potential contaminants off the floor, off the ground, and out of the drains Preventive maintenance to avoid leaks of contaminants that may later enter a water stream through washing or flushing Spill kits and procedures to handle spills if they occur Removal of snow and/or rainwater runoff from areas of contamination Infiltration and retention ponds for surface runoff Employee training Recordkeeping and reporting Facility or Process-specific - tailored to the requirements of an individual site or process. Generally used when there is a history of releases or the potential exists. Spill controls including physical or vegetative barriers Controls to prevent water running onto or over production areas that might be contaminated Splash plates Process redesign or procedure overhaul 4

5 Implementing P2 for Nonpoint Sources of Water Pollution To implement a program: Research the waste streams Harder for nonpoint source since no permits apply and measuring something that is diffuse by its nature is difficult Sometimes you just can t quantify the amount of runoff or concentration of contaminants In that case, concentrate on your best judgment as to what is happening and implementation of best management practices Tie the contaminants and quantities to the various sources Walk-throughs and visual inspections may be a key Talk to the janitorial staff and the line workers Implementing P2 for Nonpoint Sources of Water Pollution To implement a program: Best management practices exist and should be implemented even if economic payback periods can t be calculated Focus on environmental improvement Publicize what you are doing and why to employees and the public 5