Dosed-Flow Distribution

(application & distribution options)

Predetermined volumes of effluent are held in a

chamber and dosed to the next component. This

provides:

        · More uniform loading to next component.

        · Resting times between doses.

· Can be used to distribute effluent in almost any

situation.

· Costs more and is more complex than gravity flow.

· For many has become the method of choice.

· On-going monitoring & maintenance are important.

· Alarms are needed.

· Dose occurs when sufficient volume of effluent has

been collected.

· Dosing frequently depends on how much

wastewater is generated.

 Demand Dosing

· Demand dosing results in a dosing schedule that is

dictated entirely by the incoming flow and the set

points of the floats.

 Dosing Methods 

· On Demand

· Timed

 Demand Method

· Pump controlled directly by floats.

· Septic Field is dosed as system is used.

 Timed-Dosed Distribution

· A timer controls the number of doses per day and

the dose volume. 

· Will allow only a certain amount of effluent to be

dosed daily.

· A little more costly and complicated than demand.

· Protects downstream components from

overloading.

· Useful for controlling surges or big-flow days.

· Useful for infiltration monitoring.

Timed Dose

· Controlled dosing and resting of media with

predetermined dose quantities can be achieved

through use of one or more floats in conjunction with

a programmable timer.

Dosed-Flow Distribution

· Dosing devices - Pump.

· In pump tank

 Devices & Options

· Dosing Devices - Pump

· In 2nd Compartment

· Option #1: Dose to Gravity

· When drainfield is at higher elevation than septic

tank.

 Pressure Distribution- How it works

· Predtermined quantity of effluent collected.

· At predetermined volume or time, dosing device

discharges effluent to distribution network.

· Because of small pipe and orfices, distribution

network pressurizers quickly.

· Current design objectives want equal amounts of

effluent from each orfice.

 Pressure Distribution- Contents

· Laterals are typically 1-2 inches in diameter.

· Orfices are typically 1/8 to 3/16 inches in diameter.

· Depending on specific site, there is usually one

orfice every 4-15 square feet.

· Orfices can face up, down or to the side.

· Low pressures in network are typically between 2

and 5 feet of head.

tank.

 Pressure Distribution

· Uses a network of small diameter pipe and small

orfices.

 Pressure Distribution- Objectives

· Quickly pressurize network

· Be fully pressurized for most of dose

· Minimize draining into lower laterals

· Have about the same amount of effluent reach each

square foot of infiltrative surface.