WATER QUALITY Measure of substances in water other than water molecules levels of these substances are set by the Environmental Protection Agency or EPA

Potable (drinkable) water is: Clear Colorless Has a neutral pH Has correct amounts of dissolved oxygen (DO) Needed for aquatic animals and plants

TURBIDITY Cloudiness of water Caused by: erosion, runoff, algae growth, animals stirring up debri Leads to: Increased water temp  less oxygen Cold water holds more oxygen Less sun light  less photosynthesis  less oxygen These can lead to fish kills

pH – measure of how acidic or basic water is Measure on a scale of 0 – 14 Below 7 = acid Above 7 = basic 7 = neutral --- pure water

Over many years these nutrients collect in the water Waste from organisms and remains of dead organisms contain NITRATES and PHOSPHATES (found in fertilizers) Over many years these nutrients collect in the water EUTROPHICATION – build up of nutrients

Eutrophication causes more algae to grow – forms a thick green scum on the surface Blocks out the sun Decreases the amount dissolved oxygen Kills aquatic life Disrupts food webs

DISEASE CAUSING ORGANISMS Detected with a coliform count Measures E.Coli bacteria Found in poop WATER HARDNESS Measure of the concentration of calcium and magnesium Hard water does not form suds

FRESHWATER POLLUTION

What is POLLUTION? Water Pollution - addition of any substance that has a negative effect on water quality or the living things that depend on water. Pollutants – anything that causes pollution (chemicals, waste, metals, organisms, petroleum products)

Sources of pollution are classified by how they enter the water: Point Source – specific source of pollution. EX a pipe releasing waste directly into a river. Non-point Source – source of pollution that cannot be tied to a specific source. EX oil drips from a car. When it rains, the water washes the oil into a nearby creek or pond.

POINT SOURCE

NON-Point Source

EFFECTS OF POLLUTION Some effects are obvious. It is clear to see the effects of most point sources. Some non-point sources are not so obvious. EX -- Pesticides building up in the body of living things. Some pesticides such as move through food chains as organisms at different levels are eaten. The concentration of this chemical increases as you move to the top of the food chain. This build up can lead to problems like birth defects or cancer.

Three major sources of water pollution are human waste, industrial waste and chemical runoff. The connection that dumping human waste in water can spread disease was only made 150 years ago. Cholera outbreak in 1854 in England. A broken sewage pipe leaked into a common well, spreading the disease and killing hundreds in days.

TREATING WATER 1. Filtration – passing water through a screen, gets out the big pieces 2. Coagulation – adding a chemical that produces sticky globs (sink to bottom) 3. Second filtration – passing water through sand or gravel, gets out small stuff (bacteria) 4. Chlorination – adding chlorine kills bacteria. disinfects 5. Additional treatment – flouride may be added

Waste water is treated before being pumped being released or You may have a septic tank in your yard

SEPTIC TANK What is a leach field?

INDUSTRIAL WASTE More serious problem often is not treated Chemicals, smoke and heated water are common pollutants from industries.

CHEMICALS Runoff from Agriculture (fertilizer and pesticides) – lead to Eutrophication Runoff from roads

Smoke and Exhaust Burning fossil fuels leads to the formation of sulfuric and nitric acids in the atmosphere. This leads to acid rain. Rain with a pH below 7

Bioindicator Small organisms that are used to monitor the quality of a habitat (aquatic or terrestrial) These organisms respond to minimal changes in their environment May indicate unhealthy water

POLLUTIONS SOLUTIONS Clean-up and Prevention Living things filter pollutants out of water Plant roots absorb stuff Bacteria eat up toxic chemicals and oil

PREVENTION Industries: recycle and reuse water Farmers: use fewer toxic chemicals Farmers: collect runoff water to use for irrigation. plant fields of grass to filter runoff water. Dispose of chemicals like paint and oil properly We need to be good STEWARDS of our water.