July 2018

s spring turns to summer, many

systems must adjust their

treatment methods to maintain

an adequate amount of residual chlorine

throughout their distribution systems.

Longer hours of sunlight and warmer

air temperatures can heat water stored

in water storage tanks which in turn

results in a deterioration in the residual

chlorine levels throughout the system.

Surface water systems also treat

influent water that is sometimes up to

80 degrees F.

Doniphan County Rural Water

District (RWD) No. 5 is one of many

systems that must adjust the treatment

method accordingly with the onset of

warmer weather. RWD 5 does not

pump or treat their own source of

surface water or groundwater. Instead,

RWD 5 obtains water from Missouri-

American Water, whose primary source

of water is wells along the Missouri

River at St. Joseph. While Missouri-

American delivers treated water with

adequate chlorination to RWD 5’s

pumphouse in Wathena, RWD 5 must

rechlorinate that water before it enters their distribution

system in order to maintain adequate levels throughout the

system, including water sold to neighboring Doniphan

County RWD No. 2. RWD 5 typically has to rechlorinate for

only about three months each year, usually from about July

1 to September 30, depending on weather conditions.

RWD 5 uses ammonium sulfate and sodium hypochlorite

in their treatment process. The consequences of improperly

mixing these chemicals can be dangerous, if not

catastrophic. Since their water treatment equipment may be

idle for nine months of the year, a thorough overhaul is

conducted every spring to ensure that their equipment works

as needed, when needed. Such

equipment has tubing that may become

brittle with the use of chlorine and the

cold temperatures during idle months.

For several years, RWD 5 and

numerous other systems have turned to

the Kansas Rural Water Association

(KRWA) to provide technical assistance

and help bring the water treatment

systems back into proper operating

condition. This involves items such as repairing positive

displacement pumps, peristaltic pumps, chlorinators,

replacing valves and injectors, along with replacing all

feedlines and pressure transducer lines. KRWA recently

provided such assistance to Doniphan RWD 5 and in the

process tries to also train the operators on the equipment.

Once completed at Doniphan RWD 5, similar assistance

was provided to Doniphan County RWD No. 2. 

Most chemical feed pumps have design limitations due to

a variety of chemicals. For example, some may only be

designed to inject aluminum sulfate (alum)‚ ferric sulfate‚

hydrochloric acid‚ magnesium hydroxide‚ 10 percent

By Lonnie Boller, Technical Assistant    

The consequences of

improperly mixing

these chemicals can be

dangerous, if not



KRWA Assists Doniphan County 

RWDs with Overhaul of

Rechlorination Systems

KRWA Tech Assistant Lonnie Boller and Roger Engemann, Operator for Doniphan

RWD 5, work at retubing peristaltic chemical feed pumps.