This formative assessment is a modified true-false quiz. After reading the following 10 statements, determine if they are true or false, and indicate which. Then, if false, correct the bolded, underlined, italicized portion of the statement to make it true. Example: Most water pollution problems are caused by the shipping industry. ANS: F; land-based activities 1. High levels of oxygen and potassium are limiting nutrients in aquatic ecosystems. Excessive amounts of these elements can cause an algal bloom.

2. It was the Romans of the 3 rd Century, in their “cloaca maxima”, that learned the importance of carrying their waste water and storm drainage in closed conduits to the Tiber River. 3. Outbreaks of cholera and hepatitis were common during the Middle Ages in Europe, because of the ineffective waste management. 4. It wasn’t until the colonization of North America that ecological damage to local waterways became a major problem, as populations and industry grew more concentrated in ever- expanding urban areas.

5.Streams and waterways are naturally purified through the work of sunlight and organisms. 6. Today, many major U.S. cities do not permit raw, untreated sewage to be discharged directly into surface waters. 7. Modern sewage treatment first takes raw sewage and filters the solid waste from the liquid waste with a screening process.

8. Sedimentation is the act or process by which a number of individual, minute, suspended particles are clumped together and loosely aggregated or precipitated into small lumps or clusters. 9. When the sludge is put through the process where compressed air oxidizes and circulates while being digested by massive biological action, methane is a by-product. 10. The final act during sewage treatment is to disinfect the final sedimentation with ammonia, and then discharge it back into the environment.

During our lab, we are going to add alum to the wastewater. What process will we be simulating when we do this?