1. Water Treatment You have been lucky and obtained a summer job with the World Health Organization. Your assignment is to act as an engineering advisor to the mayor a small village in Central America, located in the tropical coastal flatland. The village has 200 families, about 1500 people. The majority of the families carry their water in buckets from a nearby stream. The average carry is 500 m. About 25% of the families purchase their water from a local vendor at 4 cents/gal. Five of the wealthier families have private wells on their premises. Toilet facilities throughout the village are outdoor privies. The mayor informs you that there have been incidents of various kinds of sickness, which have been caused by the local sanitation situation. He asks you for suggestions to improve the situation. a) What factors must you consider to determine whether a community water supply project should be undertaken? b) Based on your basic knowledge of the different components of a water treatment system, suggest a system that could satisfy the need for this community. c) What resources and services must the village mobilize and sustain to make a community water supply a successful venture? 2. Water Treatment The water treatment plant for a mixed industrial-commercial-residential city of 100,000 people is supplied by a river intake. The actual plant configuration consists of three parallel sets of one coagulation/flocculator tank, one sedimentation tank followed by four rapid filter boxes (See Figure 1). Normally, the turbidity of the water is 50 Turbidity Units (TU). Three or four times a year heavy rains cause the turbidity to increase to 500 TU. In addition, the sewage treatment plant of a nearby upstream town in known to release partially treated sewage at these times because of the high rate of stormwater runoff flowing through the combined stormwater and sewage lines feeding the plant. In its present configuration the plant cannot provide the required quality of drinking water during these periods and the citizens have begun to complain. Discuss the strategies open to you as the waterworks engineer for the town (at least two possible solutions). Provide conceptual solutions, no design involved