Water Unit Review of Activities 30-34

Can You Taste the Difference? In this activity, we performed taste tests on four different types of water. Distilled – water produced by boiling – removes all contaminants and minerals – purest water Spring – water obtained from an underground source that flows naturally to the surface of the earth Well - comes from the ground Tap – comes from the faucet at the sink

Main points from Activity #30 Bottled water is considered a food and falls under the Food and Drug Administration (FDA) whereas tap water is a natural resource overseen by the Environmental Protection Agency (EPA). Standards for each group are very different. We watched “Tapped” revealing the trade-offs or implications of drinking bottled water. Since only half of us actually identified each of the water sources accurately, we have limitations of human perception when it comes to water.

Willow Grove’s Troubled Waters People in Willow Grove have become uneasy about their drinking water. Their town is growing with surrounding rural areas. We analyzed the maps and tried to decide what evidence would be needed to decide whether there is a cause for alarm. Contaminants – any substance picked up by water Ted Talk Link -

Mapping Death In this activity we were introduced to a historical example of severe illness related to a water supply and the discovery of how it occurred. We read about the swift and deadly outbreak of cholera and simulated John Snow’s investigative approach to finding the source of the epidemic.

Analyzing Information From plotting the deaths on a map of London, we learned that most of the deaths were located in the center of the map around Broad Street. Who got sick? Sometimes whole families got sick and died. It seemed to have affected people of all ages and sex. Their occupations did not seem to matter except in a few cases. For example, a doctor died but it may have been because he visited so many sick people. We made hypotheses about how the disease could have spread – We for the most part decided that cholera could be spreading from either the water, direct contact, food or it could be airborne.

John Snow and the Search for Evidence Having reached the conclusion from the map that the water pump may have something to do with the cholera outbreak, we followed Dr. Snow’s search for more evidence to prove his hypothesis. We used letters and data to analyze information collected about the two water companies serving London during the cholera outbreak of 1854. (S&V and Lambeth) We discussed our evidence and identified what they thought was the reason for the outbreak and identified three pieces of evidence to support our hypotheses.

Cause of the spread of cholera Map – the map showed that many deaths occurred around the pump on Broad Street. In 1852, Lambeth switched its water intake pipe to a place 10 miles upstream on the Thames River and not many people have become sick. The pump on Broad Street has the most concentrations and has caused the most deaths. S&V continued to get its water from a spot where a lot of human waste was being dumped. Dr. Whiting researched the water supply for each household where a cholera death occurred. The data collected is that the S&V Water Company supplies 40,046 houses and caused 4,093 deaths which is about 10%. However, the Lambeth Water Company supplied 26,107 homes and caused 461 deaths which is about 1.8%. Because Lambeth moved their pipes upstream, they have had the fewest deaths, which means that their water is clean.

Water Pollution Biological contamination – living or once living organisms which cause sickness – can be found in the fecal matter of birds, animals and humans (human and animal waste along with storm water) E-coli bacteria Giardia Cryptosporidium Cholera Fox 10 news video

Water Pollution Chemical Contamination – chemical substances such as fertilizers, gasoline, oil, heavy metals and acids found in water. Main sources include – fertilizers and chemicals from farms that run off, salt from roads that run to river, copper and lead pipes, gas, oil and antifreeze from vehicles or heavy equipment, Industrial waste and mines.

Based on the information from the reading, determine which type of contamination, biological or chemical, is present in the following scenarios. Explain. Thousands of cars travel on city roads every day. The tires rub against the road and leave behind small flakes of rubber. When the brakes are used, tiny amounts of copper flake off. Eventually the rubber and copper get washed into streams and rivers. You wash your car with soap in the driveway. Soapy water drains down the gutter and into the storm drain, and eventually runs into a river, lake or bay. Scientists discovered that droppings from seagulls in a restored salt marsh were spreading to shallow ocean waters near a beach. Officials closed the beach to swimming because the bacterial contamination was thousands of times higher than the limit that people could safely be exposed to.