AWWA ABC Water Distribution Grades 1 & 2 Questions and Answers with Certified Solutions

WWA ABC Water Distribution Grades 1 & 2 Questions and Answers with Certified Solutions Which agency sets legal limits on the concentration levels of harmful contaminants in potable water distributed to customers? US Environmental Protection Agency The number of monthly distributions system bacteriologiacal samples required is Based on the population served What is the maximum contaminant level for total trihalomethanes (TTHM) in the united States? 0.080 mg/L Under the Surface Water Treatment Rule, disinfection residuals must be collected at the same location in the distribution system as coliform samples Iron can cause "red water" and thus customer complaints when its concentration is above its secondary maximum contaminant level of 0.30 mg/L The goal of the Surface Drinking Water Act is for each ________ to accept primary enforcement responsibility (primacy) for the operation of the state's drinking water program. State What is the objective of Total Coliform Rule? To promote routine surveillance of distribution system water quality to search for fecal matter and/or disease-causing bacteria Which agency sets standards on the concentration levels of harmful contaminants in drinking water? EPA Explain the difference between the different tiers of violations. Which tier is the most serious? Tier 1 = 24 hours (most severe) Tier 2= 30 days Tier 3= 1 year A positive E. Coli test must be reported to the primacy health agency within what time period? 24 hours How is the required number of monthly bacteriological samples determined? Population served What is the action level for lead in first-draw samples taken from customer taps? 0.015 mg/L A water system is designated a community public water system if it serves how many homes? 15 or more What authority provides specific water sampling instructions? The state primacy agency According to the Lead and Copper Rule, what is the action level for lead? 0.015 mg/L Head is measured in Feet A plat is a map At which time of the day is the age of the water stored in the distribution system the highest? Early morning Water mains should primarily be sized based on adequate fire flow at an appropriate pressure The most desirable residential pressure ranges from 50 to 75 psi (345 to 517kPa) Domestic water use includes water that is supplied to residential areas, ____________, and institutional facilities. commercial districts Riparian doctrine is sometimes called the "rule of reasonable sharing." During which season is water typically the highest? summer Of the common types of distribution system, which type is considered least desirable? Tree system The velocity of water is calculated as the quantity of water that flows through a pipe divided by the cross-sectional area of pipe What is the term for water pressure in a main or in a container that is measured by a gauge? Gage pressure In hydraulics, how is head expressed? ft-pounds per pound What is the term for pressure measured in terms of the height of water ( in meters or feet)? Head What are three types of head? Elevation head velocity head pressure head The highest degree of protection for the exterior of a coating steel pipe is Cathodic protection The C value is a measure of a pipe wall's roughness, which retards flow due to friction. Type of joint for ductile iron piping? Push-on joint What is the term for a sudden repeated increase and decrease in pr