What gas can cause lung and skin irritation?

Shellfish grown in polluted waters have been known to contain the organism that causes infectious hepatitis.

In a thermally stratified reservoir, water located beneath the thermocline may?

What will cause reverse osmosis membranes to compact faster?

Why is it important to reduce turbidity?

Once they become fouled, how are reverse osmosis membranes cleaned?

When should polyphosphates used for sequestration of iron and manganese from a well be injected?

Waterborne diseases like typhoid and cholera are caused by?

What effect will an increase in total dissolved solids in water to be treated be?

Water that is softened has a high pH and a high concentration of CaCO3. Therefore stabilization is essential in order to prevent the CaCO3 from precipitating out on?

Every 1.0 mg/L of alum consumes what amount of alkalinity during the formation of floc particles?

A method to increase or maintain the DO concentration of a thermally stratified reservoir?

Protozoa that must be removed from raw water are?

During filtration, what role does the action of straining of suspended particles play?

What is a universal solvent?

For lime-soda ash softening plants, what is the most economical sludge disposal method?

Manganese is rarely found in surface waters above a concentration of?

What sludge dewatering process requires a pre-coat of diatomaceous earth and its use has declined due to other newer methods?

The actions levels for lead and copper are?

The release of dissolved gasses in saturated cold water when pressure decreases in filter beds causes?

If the continuous monitoring of the residual disinfectant concentration of the water entering the water system fails, how often will an operator need to collect a grab sample until the problem is fixed?

Chlorine gas ton cylinders include two feed line connections. One is an upper and one is a lower that is designed to?

The IDLH (immediately dangerous to life and health) value for chlorine is?

The backwash rate must be high enough to?

What chemical can be added to the water system to sequester Iron and Manganese?

When a permit is required to enter a confined space, who may sign the permit?

Why are check valves installed in suction lines?

Adding CO2 to water will?

What is the most probable solution if crustaceans have clogged the water treatment plant's filters?

What is the usual range of percent sludge solids, if the sludge is allowed to accumulate and compact at the bottom of a sedimentation basin?

Chloramination is?

If the chlorine demand suddenly increases from 0.4 mg/L to 2.8 mg/L, what could be the reason?

What is the most favorable raw water condition for good flocculation?

What chemical oxidant is most effective in reducing the concentration of taste and odor compounds caused by actinomycetes species?

Records of chemical analyses should be kept for?

If ammonia vapor is passed over a chlorine leak in a cylinder valve, the leak is indicate by

What water quality indicator is of greatest concern in a surface water treatment plant?

What is the typical strength of calcium hypochlorite?

Filtration rates vary from what of filter surface area?

As the level of phosphates increase in a new water supply, an operator should?

Which is the strongest disinfectant?

Trihalomethanes (THM's) are primarily a concern in?

What is the depression around the well of the water surface caused by pumping water from a well?

Potassium Permanganate should be?

In which state are Giardia most vulnerable to inactivation through disinfection?

For alum coagulation of color, what is the correct pH?

What is the usual effective pH range of iron salt coagulants?

The porous material just above the water table that holds small quantities of water by capillary action is called?

What is the most advantageous application point for powdered activated carbon?

A connection between a potable water system and a non potable water system is?