Chapter 5 - Water Treatment & Purification Flashcards
What are water sources developed for military use referenced as?
Water points.
What are examples of surface water?
Streams, lakes and rivers.
What does the amount of precipitation, the size of the drain area, geology, ground surface, evaporation, temperature, typography, and artificial controls determine?
This determines the amount of water that collects in any surface source.
How many gallons of water are in a cubic foot?
7.5 gallons of water.
How many gallons of water are in a cubic foot that has to account for error and stream measurement?
6.4 gallons.
What formula would you use to calculate a flowing streams quantity of water in gallons per minute?
Q= 6.4 x A x V
What does the Q stand for in the formula that determines GPM in a flowing stream?
Q = quantity of water in gallons per minute.
What does the A stand for in the formula that determines GPM in a flowing stream?
A= Area of the stream.
How would you obtain the area (A) of a stream in square feet?
By multiplying the width times the average depth of the stream.
What does the V stand for in the formula that determines GPM in a flowing stream?
The velocity of the stream in feet per minute.
How would you obtain the velocity (V) of the stream and feet per minute?
By measuring the time it takes for a floating object to travel a known distance, such as a twig flowing at 13.3 ft./m.
A stream having an average depth of 2 feet, a width of 16 feet, and a twig is noted to flow at 13.3 ft./m. Calculate the quantity of water and gallons per minute flowing in the stream.
Q= 6.4 x A x V Q= 6.4 x (2x16) x 13.3 Q= 6.4 x 32 x 13.3 Q= 2,723.84 gpm
What are three factors you must consider when selecting a water source?
Quantity, quality, and reliability.
What formula would you use to calculate the quantity of water in a lake or pond having little or no run off?
Q= A x D x 7.5
What does the A stand for in the formula that determines GPM in a Lake or pond having little or no run off?
Surface area.
What does the D stand for in the formula that determines GPM in a Lake or pond having little or no run off?
Average depth.
How many gallons per cubic feet are inside of a pond or lake that has little to no run off?
7.5 gallons per cubic foot.
What does the Q stand for in the formula that determines GPM in a Lake or pond that has little to no run off?
Q = quantity of water in gallons per minute.
If a pond or lake has an average depth of 7 feet and a surface area of 2864 ft.² how many gallons is inside of this pond or lake?
Q= A x D x 7.5 Q= 2,864 x 7 x 7.5 Q= 150,360 gallons
What bodies of water are usually located within the water table?
Lakes and ponds.
How would you calculate the quantity of water that can be supplied from newly constructed or existing wells?
By making a drawdown test.
When conducting a drawdown test how many feet would you draw down the static water level to record it’s recovery time?
1 to 2 feet.
What is a static water level inside of a well?
It’s when the level inside of the well is the same level as the water table.
What is the water table?
It is the water beneath the ground.
How would you obtain a static water level?
By measuring the distance of the ground surface to the static water level.
If a water level in a well is 25 feet below ground what is the static water level for this well?
The static water level for this well is 25 feet.
When a water well is pumping for several hours at a constant rate it stabilizes itself in a lower position what is this called?
This is called the pumping level.
What is another name for the pumping level?
Dynamic water level.
When water beneath the ground is lowered by pumping what is this distance called?
The distance the water is lowered by pumping is called the drawdown.
What is the drawdown inside of a well?
It is the difference between the static water level and the pumping level.
When drawdown occurs inside of a well resulting from pumping what does this do to the water pressure in the well?
It lowers the water pressure inside of the wall.
If water pressure is lowered inside of a well what happens to the surrounding water beer in formation pressure?
It retains its original pressure.
When the water bearing formation pressure is different from the water pressure inside of the well what does this result in?
It makes water flow out of the pores from the formation into the well.
What is a term used to describe the characteristics of a porous material?
Permeability.
What are the factors that would affect the rate of flow within a water well?
The frictional resistance to flow developed within the aquifer formation a.k.a. the permeability of the formation to give out water.
What factor affects the quantity of water a formation can supply to a water well?
The amount of water and aquifer can supply is directly proportional to the permeability of the formation (aquifer).
What does the volume of water pumped per minute or per hour, the depth to the static water level before pumping is started, the depth to the pumping level at one or more constant rates of pumping, the recovery of the water level after pumping is stopped, and the length of time the well is pumped at each rate provide you with when working with waterwells?
The measurements that should be made in testing water wells for its hydraulic characteristics.
What should the pump and power unit used for testing a well be capable of?
Continuous operation at a constant and variable-rate a pump which for a period of over 24 hours.
At a minimum how long should pumping tests of water well occur?
The test should run at least 24 hours.
How would you be able to verify the adequacy of a water well formation?
By running longer pumping tests, up to several weeks in duration.
By ensuring that the pump will operate at a rate that will case only about 50% of the maximum possible drawdown what are you doing?
You are determining the safe yield of a well.
Inside of a water well the drawdown should not exceed a point of how many feet above the top most screen slot?
5 feet.
What includes initial static water levels, pumping right at least every hour, drawdown data at least every hour and rate of recovery?
The complete water well test report.
What is the safe pumping yield for water wells?
A withdrawal rate that doesn’t cause a lowering of the water table and goes no more than 50% of the maximum drawdown.
When using a catch tank to record gallons per minute from water wells how many minutes at a minimum should just catch tank be rated for?
At least two minutes.
When using a catch tank with a capacity of storing two minutes of water to record gallons per minute from a water well what is the limitation to this method?
Since attached tank is so small you can only use it for small wells.
What instrument offers a definite advantage and measuring water being pumped from water well?
Water meters.
What instrument has the capability of recording the total discharge for any individual phase of a drawdown test?
Water meters.
What is the most accurate way to measure depth to the static level and to the pumping level in a water well?
With chalked tape.
How many feet of chalked tape should be submerged when measuring the depth of the static level to the pumping level inside of a water well?
1 to 2 feet of the tape is submerged.
What are you trying to find when you divide the water wells yield or discharge in gallons per minute divided by the drawdown and feet?
You’re trying to find the specific capacity of the well.
What is more dangerous to health when found in water, suspended or dissolved impurities?
Suspended impurities are usually more dangerous to health.
Mineral matter, disease organisms, salt, bacteria and algae are all examples of what inside of water?
Suspended impurities.
How would you find an impurity in the water that cannot be seen by the naked guy?
By conducting laboratory tests only.
What calcium and magnesium based impurities cause alkalinity hardness in water?
Bicarbonate
Carbonate.
What calcium and magnesium based impurities cause hardness within water?
Sulfate.
What calcium and magnesium based impurities cause harness that is corrosive to boilers?
Chloride.
What sodium based impurities cause alkalinity within water?
Bicarbonate
Carbonate.
What impurity causes foaming in steam boilers?
Sulfate.
What impurity inside of water causes mottled enamel teeth?
Fluoride.
What dissolved in purity causes a salty taste inside of water?
Chloride.
What dissolved in purity causes Redwater and encrusts on metals?
Iron.
What dissolved impurity causes black or brown water?
Manganese.
What does all the purity causes color and acidity?
Vegetable dye.
What dissolved gas based impurity inside of water causes corrosion of metals?
Oxygen.
What gas based impurity cause acidity and corrosion of metals?
Carbon dioxide.
What dissolved gas impurity causes odor, acidity and the corrosion of metals?
Hydrogen sulfide.
What gas based impurity has no effect within water?
Nitrogen.
Why would you forward water samples to a laboratory?
For complete mineral or bacteriological analysis.
How would you know what variations to expect at water sources?
By studying the hydrological data.
What may control the amount of water flowing and the rate of flow within a water well?
Geological layers.
What level is the title to ground and surface water in the United States usually regulated at?
The state level.
What type of waters are under federal control?
Navigable waters having interstate traffic.
A total of how many gallons per minute or flowing stream that is 10 feet wide and has an average depth of 3 feet when the water is flowing at a velocity of 15 ft./m?
Q= A x V x 6.4 Q= (10x3) x 15 x 6.4 Q= 2,880 GPM
What sources are used to increase the quantity and quality of water?
Dams, floats, galleries, and similar improvements may be used.