Texas Class D Water License(Complete)Questions And Answers.

Texas Class D Water License(Complete)Questions And Answers. What removes tastes, odors, and certain organics and gases, and oxidizes iron and manganese? This process includes the incorporation of air into the water by means of spray nozzles , steps or cascades, or trays of diffusers? Aeration TCEQ regulation states that Shore installations , marinas, boats and houses on the watershed must have sewage? disposal Water aerated or chlorinated at proper pH levels oxidizes the iron and manganese, turning them into solid? particles Well casing and cementing protect the well from collapse and surface ? contamination Sequestering does not remove iron from the water, but prevents it from combining with oxygen and? reddening The quantity of water a formation yields depends on the formations thickness and? permeability Cascade aerators, packed air-stripping towers, and air diffusers are used to aerate? water Aeration can be used to remove what from the water supply? iron and manganese Hydrogen sulfide has a rotten egg odor and is oxidized by? super-chlorination When Iron levels get this high, it can cause red stains on clothing, colored water, or turbidity? 0.3 mg/L Excess Manganese can cause? black stains Another method of iron control is the use of? sequestering agents What is a sequestering agent? polyphosphates Well water is sometimes? corrosive Low ph, dissolved gases, high temperatures, and high mineral levels can cause well water to be? corrosive What is the process of removing calcium and magnesium by adding lime or by exchanging ions? softening An ion exchange replaces calcium ions with? sodium ions A process available for removing arsenic, fluoride, lead, mercury, nitrate, and silver from raw water is? coagulation followed by sedimentation and filtration A process that forces water through a membrane is? reverse osmosis In reverse osmosis a sheet of synthetic material (membrane) under pressure prevents passage of dissolved materials and larger particles and ejects them in a? waste stream The Surface Water Treatment Rule (SWTR) requires community and non-community wells, springs, and infiltration galleries ( a subsurface tunnel that collects groundwater) to determine possible direct influence of? surface water Changes in groundwater quality can indicate influence of surface water organisms such as giardia cysts, algae or other? microorganisms If well is deeper than 50 feet and more than 200 feet from a nearby surface water body, extensive evaluation of the influence of surface water on a water supply is? not required Surface water evaluations are needed on a water supply when shifts in water quality occur such as turbidity, temperature, pH, and the presence of? surface water organisms What are underground, water-bearing formations yielding useful quantities of water? Aquifiers Problems caused by what are declining water levels and subsidence (sinking of land)? overpumping The purpose of the well screen is to keep out birds and? sand the most important feature of the well screen is the size of the? opening The mesh size of the screen is determined by the size of the aquifer material, the size of the gravel in the gravel pack, and the type of well ? development The gravel pack is fine gravel placed around the screen to reduce pumping? sand The well vent is a vacuum breaker allowing the casing to breathe as water levels change when the pump? cycles All public wells must be provided with a steel sealing block, a meter, a screened vent, and a sampling? faucet No source of contamination is allowed within how many feet of a public well? 50 One way to reduce sand pumping is to decrease the pump rate and cycle? less Water from a new well must not be used until bacteriological samples on three successive days show no? coliform Groundwater usually contains more dissolved minerals and gases than surface water but fewer? microorganisms Water table wells are usually? shallow In a water table well, the cone of depression and area around the well is? dewatered A sanitary control easement must cover land within how many feet of a public well? 150 Livestock and septic tanks must be no closer than how many feet of a public well? 50 Underground fuel tanks and septic drainage fields must be at least how many feet from a public well? 150 Feedlots, sewage treatment plants, and landfills must be at least how many feet from a public well? 500 A well may be developed by surging, overpumping, jetting, and? backwashing To disinfect a new well, a chlorine dosage of at least how much is required? 50 mg/L A sample for physical and chemical analysis must be taken after how many hours of pumping in a well? 36 hours Changes in well water levels or the volume of water produced can alert the operator to a drop in the water table, screen stoppage, or damage to the? pump What are 2 common deep well pumps? submersible and vertical turbine Gases such as methane , carbon dioxide, and hydrogen sulfide are reduced by? aeration Rivers, lakes and what are surface water sources? reservoirs Texas has how many major river basins 23 What is the longest running river in Texas? Rio Grande A major reservoir contains at least how many acre-feet?