Please answer the questions below based on the readings and lectures provided. Your answers should be complete and to the point. This assignment is worth 15 total points (each question provides the breakdown).

1. (a) Define backflow and distinguish between the two types of backflow. (b) Give an example of a cross connection. (c) Comment on their frequency, their causes, and what can be done to prevent them. [1 pt for each part = 3 pts]

2. (a) Define desalination [0.5 pt]. (b) Comment on the salinity of the source water vs. freshwater [0.5 pt]. (c) Identify and discuss operational requirements and associated concerns for running a desalination facility [1 pt]. (d) Highlight the number of desalination facilities and future trends [1 pt]. [3 pts total]

3. Regarding distribution system management, (a) discuss relevant operational considerations (e.g., disinfectant residual, piping materials, operating pressure, contamination, water quality sampling, corrosion). (b) What encourages biofilm regrowth and what preventative measures may be taken to control its occurrence? [2 pts for (a), 1 pt for (b) = 3 pts]

4. (a) Compare/contrast unidirectional and traditional flushing. (b) Discuss the operations, considerations, and benefits of unidirectional flushing. [1.5 pts for each part = 3 pts]

5. For each of the following rules, identify (a) what systems it applies to, (b) what contaminants it addresses, (c) what other requirements it is associated with, and (d) the benefits projected, and corresponding costs: (1) Stage 2 Disinfection/DBP Rule; (2) Groundwater Rule; (3) Long Term 2 Enhanced Surface Water Treatment Rule. [1 pt for each rule = 3 pts]

Drinking Water