WATER POLLUTION Chapter 11

What is Pollution? 1.Describe water pollution that you have seen 2.Why do you believe that it was pollution? 3.What sensory cues did you use? 4.Why did this info tell you it was pollution?

Pollution Any chemical, biological, or physical change in water quality that has a harmful effect on living organisms or makes water unsuitable

How would you define a point source and a nonpoint source?

Where does the pollution come from? Point source = single, identifiable source -can you point your finger at the polluter? Nonpoint source = many sources, hard to identify -the pollution could be from many sources – hard to point your finger at the culprit

Point Sources of Pollution Gets into the water from… –Pipes, ditches, sewers into bodies of surface water Some examples… 1.sewage treatment plants 2.Factories 3.Landfills 4.Mines 5.Oil wells

Non-Point Sources of Pollution Gets into the water from… –Runoff, subsurface flow, air Some examples… 1. Soil from construction sites and farms 2. Storm-water runoff (oil, dog poop, litter, gas) 3. Pesticides and fertilizers 4. Agricultural feces 5. Salt for snow and ice

Which is a bigger problem? ~ Nonpoint source pollution Which is easier to eliminate? ~ Point source pollution

Types of Pollution Chemical Thermal Artificial Eutrophication Genetic Ocean Groundwater Wastewater

Artificial Eutrophication Algal blooms caused by too much Nitrate and Phosphate in the water Reaches the water by runoff from farms 2. lawns 3. sewage treatment plants

Remember why nutrients are bad… Too much N and P leads to LOTS of plant growth –mostly algae Eventually block out sun Plants die  increase decomposers  use up O 2  kill fish

Gulf of Mexico Dead Zone

Thermal pollution Factories use water in cooling systems, then discharge warm water into streams Hot water lowers dissolved O 2 = fish kill

Genetic Pollution Invasive species hitch a ride on boats Get into the water and take over –Zebra mussels causing native mussels to die clog up intake pipes

Ocean Pollution Trash –The Great Pacific garbage patchThe Great Pacific garbage patch Oil Spills –Exxon Valdez –BP Deepwater Horizon Sewage - Combined Sewer Overflows

Combined Sewer Overflow

Groundwater Pollution Percolation and Seepage

Surface water vs. Groundwater Which is generally more polluted? ~ Surface Water Which is harder to clean up? ~ Groundwater

Groundwater pollution sticks around... Very cold, no bacterial breakdown Very slow water movement: recharge can take 100’s or 1000’s of years Pollutants can stick to rocks in aquifer and pollute new water

Case Study: Natural Gas Drilling Marcellus Shale Fracking - Hydraulic Fracturing Loophole in Safe Water Drinking Act –natural gas companies don’t have to disclose chemicals being used

How can we protect groundwater? Prevention is the key… –Monitor aquifers & landfills –Requirements for old fuel tanks Leak detection system Liability insurance –Stricter regulations on toxic waste disposal Above-ground storage of toxic waste...but then you have toxic mud spills!

Water pollution laws 1.Recreation: Water fit for fishing and swimming, cleaned up locally (1972 Clean Water Act) 2.Oceans: Controlled dumping of waste and required double hulled tankers to prevent oil spills (Oil Pollution Act) 3.Drinking Water: Protect groundwater and surface water from pollution (1975 Safe Drinking Water Act)