1 / 17

Water Quality

Water Quality. Water quality problems in developing countries. Evidence from the WHO: In 2003, an estimated 1.6 million deaths worldwide were caused by unsafe drinking water and sanitation 90% of these deaths were among children under age five

erika
Télécharger la présentation

Water Quality

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. Water Quality

  2. Water quality problems in developing countries • Evidence from the WHO: • In 2003, an estimated 1.6 million deaths worldwide were caused by unsafe drinking water and sanitation • 90% of these deaths were among children under age five • 1.1 billion people don’t have access to improved water sources • 2.4 billion people don’t have access to improved sanitation Source: www.who.int/water_sanitation_health/wsh0404/en/

  3. Water quality problems in developing countries • Biggest water quality problem in developing countries is the threat of infectious diarrhea caused by water-borne diseases. • If there was a 50% reduction in the number of people lacking access to in-house piped water and sewer connections with partial treatment of waste waters, the number of illnesses would be reduced by an average of 69% in affected regions. • http://www.who.int/water_sanitation_health/hygiene/envsan/lookingback/en/

  4. Water quality problems in the U.S. The Cuyahoga River Fire in 1969 • Floating debris and oil caught fire on the surface of the Cuyahoga River near downtown Cleveland in 1969. • The Cuyahoga River had also ignited a couple of times in earlier years. • The Cuyahoga River fire brought water-quality problems to the attention of the public and Congress. Photos: http://www.cwru.edu/artsci/engl/marling/60s/pages/richoux/Photographs.html

  5. Water quality problems in the U.S. Cryptosporidium contamination in Milwaukee in 1993 • Cryptosporidium is a protozoan parasite that’s usually present at low levels in water supplies. • An outbreak of cryptosporidium contamination in 1993 in Milwaukee caused diarrhea, fever, and other symptoms for over 400,000 residents and killed more than 100. • The contamination was traced to a water treatment plant that had inadequately filtered water from Lake Michigan. • It is believed that the original source of the contamination was storm runoff from nearby farms.

  6. Water quality problems in the U.S. Narrowing the focus: • Surface water pollution • Groundwater pollution Types of surface water pollution: • Pollution from point sources • Nonpoint-source pollution Regulation depends on designated uses of surface water: • Drinking water supply • Recreational uses (such as swimming) • Aquatic life support • Fish consumption • etc.

  7. Examples of Water Contaminants • Contaminants affecting human health: • Organic compounds (such as pesticides and gasoline) • Heavy metals (such as mercury and lead) • Pathogens (such as cryptosporidium) • Contaminants affecting aquatic life: • Plant nutrients, including nitrate and phosphorus compounds • Organic wastes, which lead to depletion of dissolved oxygen in the water

  8. Federal Water Quality Legislation • Federal Water Pollution Control Act of 1972 • Clean Water Act of 1977 • Water Quality Act of 1987 • “The Year of Clean Water”: 2002-3

  9. Water Quality Control: An Overview • Control of point-source pollution • Federal government sets water-quality standards • States create pollution-control programs to meet the standards • Programs usually require polluters to install certain pollution-control technologies • Subsidies for construction of Publicly Owned Treatment Works (POTWs) • Control of non-point source pollution

  10. Water Quality Control: An Overview The effect that a particular effluent has on water quality depends on a number of factors such as: • biochemical oxygen demand in the effluent • time of year and water temperature • location of waste sources • turbulence of water flow • volume of water flow A perfect water pollution control policy would have to take all these factors into account. Since this is impractical, actual policies involve compromises.

  11. The Oxygen Sag Curve

  12. Water Treatment Facilities • Since 1970 the federal government has spent over $60 billion to subsidize construction of POTWs, and total spending by all levels of government has been over $200 billion. • Evidence suggests that federal funding for POTW construction has largely just replaced local funding – about 67% of construction would have taken place anyway. • Federal subsidies provided perverse incentives at first: • Municipalities had an incentive to build POTWs that were too large. • Federal funding didn’t help to cover operating expenses and maintenance. • But more responsibility has been shifted to local authorities. • Progress has been significant: http://www.epa.gov/owm/wquality/

  13. Control of Other Point Sources • Basic federal program: National Pollutant Discharge Elimination System (NPDES) • Administered through a system of permits that set effluent limits; but these permits are typically not tradable. • Goal is zero discharge; but limits are usually based largely on what level of control is technically feasible. • Efficiency? Cost-effectiveness? EPA – Envirofacts WDNR - WPDES Permit Program

  14. Point-Source Control: Other Options • Effluent taxes or fees? • In theory, this is could be an effective approach. • Effluent taxes have been used in Europe, but the taxes are usually set too low to provide strong incentives to reduce pollution levels. • Best example: the Netherlands has used effluent fees as an effective pollution-control approach. • Why not use effluent taxes? • Political objections • Concerns that taxed firms will face a competitive disadvantage • Effluent taxes require careful monitoring of discharges

  15. Point-Source Control: Other Options • Tradable effluent permits • EPA > Watersheds > Trading > Frequently Asked Questions About Water Quality Trading • Advantages of effluent permit trading • Cost-effectiveness • Problems with effluent permit trading • Hot spots?

  16. Control of Pollution from Non-Point Sources • Major remaining water pollution problem, especially in agricultural states like Wisconsin. • Two important sources: • Agricultural runoff • Storm runoff

  17. Control of Pollution from Non-Point Sources • Control of agricultural runoff: the DNR provides: • Technical assistance to farmers • Subsidies for improvements to prevent runoff • Performance standards • Control of storm runoff • Storm runoff performance standards for industry, municipalities, and construction sites • In Eau Claire, new businesses must pay fees based on their likely runoff.

More Related