1 / 34

Management of Non-Point Source Pollution CE 296B

Management of Non-Point Source Pollution CE 296B. Department of Civil Engineering California State University, Sacramento. Lecture #17, April 14, 1998 Management Strategies - Part I.

amergin
Télécharger la présentation

Management of Non-Point Source Pollution CE 296B

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript


  1. Management of Non-Point Source PollutionCE 296B Department of Civil Engineering California State University, Sacramento Lecture #17, April 14, 1998 Management Strategies - Part I

  2. I. As we have stated repeatedly, the strategy for management of non-point source pollution is to implement a comprehensive program of Best Management Practices (BMP’s). As there are a mind numbing variety to chose from, we will start with the categories of BMP’s. These categories are where the BMP’s appear with respect to the “pipe”, not the BAT, BCT, and MEP categories.

  3. I. Categories of BMP’s (cont.) A. Location with respect to where the pollution is coming from and where it is going: • Front of the pipe • In the middle of the pipe • End of the pipe • BMP’s that don’t seem to be associated with the pipe at all.

  4. Watershed Receiving Water Storm or Combined Sewer Small Watercourse Overland Flow Defining the Pipe - I • We have, are, and will be using the term “pipe” repeatedly. • What is the “pipe”? “Pipes” Polluting Activities

  5. Defining the Pipe - II • Thus, we have three zones associated with the “pipe”: • The watershed, where human activities make pollutants ready to be transported by either placing them on the surface or disturbing the surface. • The receiving water, where the pollutants end up. • The means of conveyance (the “pipe”), for moving the pollutants from the “point of pollution” to the receiving water.

  6. Discussion Break For most of this class, we have been drawing links between the “needs” of the receiving water and what occurs in that watershed that could have a negative impact on the receiving water. The primary focus of current regulations and practice is to generically try to stop anything and everything (that can be regulated), capable in a generic sense of harming the receiving water, from getting to the receiving water through BMP’s. Pros and cons of these two ideas?

  7. I. Categories of BMP’s (cont.) B. At the front of the pipe, categories could include: • BMP’s that seek to minimize the use of a substance that could be a pollutant. • BMP’s that seek to adjust peoples behavior. • BMP’s that seek to keep pollutants in their place. • BMP’s that seek to prevent pollutants that have been mobilized from entering the pipe.

  8. I. Categories of BMP’s (cont.) C. In the middle of pipe, categories could include: • BMP’s that seek through structural means to halt the progress of the pollutants in the pipe. • BMP’s that involve the adjustment of the landscape to halt the transport of pollutants over significant stretches of sheet flow.

  9. I. Categories of BMP’s (cont.) D. At the end of the pipe, categories could include: • BMP’s that use physical phenomena such as settling or adsorption to remove pollutants from the flow using structural devices. • BMP’s that borrow ideas from nature to polish the flow.

  10. I. Categories of BMP’s (cont.) E. BMP’s that don’t seem to be associated with the pipe at all: • BMP’s that, in an organization, seek to establish accountability for the prevention of pollution. • BMP’s that seek to build general public awareness of non-point source pollution.

  11. II. Front-of-Pipe BMP’s A. Recall the different types of front of pipe BMP’s: • BMP’s that seek to minimize the use of a substance that could be a pollutant. • BMP’s that seek to adjust peoples behavior. • BMP’s that seek to keep pollutants in their place. • BMP’s that seek to prevent pollutants that have been mobilized from entering the pipe.

  12. II. Front-of-Pipe BMP’s (cont.) B. Pollutant use minimization, two headings, methods for minimization and means of achieving: 1. Methods: • Proper use, examples include: • Pesticide application rates • Fertilizer application rates • Product substitution, examples include: • Use of non-chlorinated solvents • Tires that contain much less zinc.

  13. II. Front-of-Pipe BMP’s (cont.) • B. Pollutant use minimization, two headings, methods for minimization and means of achieving: • 1. Methods: (cont.) • Product use restriction, including: • Bans on sales or use. • Requirements on maximum use in an area through laws and regulations. • Land use adjustments, examples include: • Change in landscaping types towards plants that requireless fertilizer, pesticides, etc. • Zoning changes

  14. II. Front-of-Pipe BMP’s (cont.) • B. Pollutant use minimization, two headings, methods for minimization and means of achieving: (cont.) 2. Means: • Educational campaigns: • For the general public, posters, advertisements, mass mailings. • For industry, more coercive approaches in getting people to listen. • Banning the sale of, and if possible the use of, the offending substance.  la charcoal lighter fluid in Southern California.

  15. Side Note Chlordane has been banned for some time. It still appears in most samples of non-point source run-off in Southern California. Under the “strict liability” standard of the Federal Clean Water Act, dischargers could in theory still be held responsible for any negative impacts these discharges still have. Also, a county that would like to ban a substance but can not, say diazanon, falls under the same standard.

  16. II. Front-of-Pipe BMP’s (cont.) • B. Pollutant use minimization, two headings, methods for minimization and means of achieving: (cont.) • 2. Means: (cont.) • Encourage land use types through the use of zoning, that are associated with lower use rates of the offending substances. • Government interference in the market place relating to the substance in question. As an example, substantially tax the cost of the offending substance. Encourage the use of substitutes.

  17. Discussion Break There is an “article of faith” among some that if the government interferes in the market place in certain ways, the free market will come up with alternatives. Success story, sort of: Banning future use of ozone depleting coolants has lead to the development of better (but more expensive) substitutes. Failure, up till now anyway: Electric car mandates leading to the development of commercially realistic ZEV’s. Examples that might or might not work in the non-point source pollution area?

  18. II. Front-of-Pipe BMP’s (cont.) • B. Pollutant use minimization, two headings, methods for minimization and means of achieving: (cont.) • 2. Means: (cont.) • Sponsor research into better products and then hope the market place works or again make adjustments to the market place. • Pass laws that allow the direct regulation of the offending substance. Tends to work in industrial and commercial settings much better than in home settings.

  19. Discussion Break What are some of the pitfalls of use minimization strategies with respect to industrial and commercial applications? Both active persuasion and regulation schemes. What are some of the driving forces beneath these problems? Are they likely to go away in the future?

  20. II. Front-of-Pipe BMP’s (cont.) C. Adjusting peoples behavior. 1. These are, in many ways, BMP’s that improve the performance of other “front-of-pipe” BMP’s. These are public education programs to help make people aware of non-point source pollution issues and to encourage them to adopt practices that produce fewer pollutants.

  21. II. Front-of-Pipe BMP’s (cont.) • C. Adjusting peoples behavior. (cont.) 2. Who is the “public” in public education programs? It is more than the obvious. • The obvious is the general public. • Entities that shares a common interest or activity. Example: Different transportation agencies and users of transportation facilities cooperation and educating each other. • Entities hydraulically connected to one another, educating each other about the mutual concerns. Example: Cooperation between entities on dealing with spilled hazardous waste.

  22. II. Front-of-Pipe BMP’s (cont.) D. Keeping pollutants immobilized. Two principle categories come to mind here, BMP’s associated with construction and BMP’s associated with existing facilities. 1. Construction sites. The primary feature of a construction site that is of concern with respect to non-point source pollution is that plant growth has been removed and erosion may carry sediment away from the site to the “pipe”. The list here is quite long. We will look at selected examples:

  23. Discharge to water course Sediment control measure Pump Perched groundwater Construction Site BMP - Dewatering Operations Shallow water, pumped out to facilitate construction operations may contain sediment and/or chemical pollutants. The discharge from the dewatering operations is treated to remove pollutants.

  24. Construction Site BMP - Concrete Waste Management Most common form of managing concrete waste is to have a concrete wash-out area. After the delivery truck has finished pouring, the delivery appurtenances are washed in an area surrounded by a dyke.

  25. Construction Site BMP - Vehicle and Equipment Cleaning Similar to the concrete washout system. Before a vehicle leaves the job site, it is washed off in an area designed to catch the sediment cleaned off the equipment.

  26. To Sediment Control Device Construction Site BMP - Outlet Tire Wash At exit of construction site, temporary wash racks are established at outlet to construction site to wash mud, water is often sprayed at construction sites to suppress dust - Clean Air Act Regulations, of tires of construction vehicles. This is to limit the placing of soil on paved surfaces outside of construction site.

  27. Cool Trees Warning Barriers Construction Site BMP - Preservation of Existing Vegetation Provide barriers and warnings to prevent construction operations from damaging vegetation that is to be preserved. Used to minimize erosion.

  28. Construction Site BMP - Temporary Seeding and Planting Plant material on disturbed ground that will not be part of construction operations for a period of time. Use of hydroseeding is an example. Works to limit erosion.

  29. Construction Site BMP - Mulching Addition of organic material, compost as an expensive example, to disturbed ground to limit erosion and to accelerate post construction plant growth.

  30. Water Flow Direction Construction Site BMP - Geotextiles, Mats/Plastic Covers and Erosion Control Blankets Placement, both temporary and permanent, of flexible material over piles or steep disturbed ground. Meant to limit erosion.

  31. Traffic Flow Construction Site BMP - Temporary Stream Crossing If a perennial or ephemeral waterway must be crossed as a result of construction operations, construction of a temporary culvert or bridge to minimize erosion where traffic crosses stream.

  32. Construction Site BMP - Slope Drains and Subsurface Drains If a channel of water down a steep slope is inevitable, a temporary drain may be installed during construction operations to limit erosion.

  33. Silt Fence Imbedded in ground Toe of Slope Construction Site BMP - Silt Fences Silt fences placed at the base of disturbed ground to capture particulate material and allow water through. Requires considerable skill to place properly. Idea is to keep sediment on site.

  34. Construction Site BMP - Storm Drain Inlet Protection Placing a barrier around existing storm drains when surrounding ground is disturbed due to construction operations. Idea is to let water pass and retain particulate material.

More Related