Surface irrigation and pump-out tanks

Low cost wastewater treatment for the world

Use the system design page for guidance on design. 

The construction pages:

Use the system design page to guide how your system should be constructed. This page is dedicated to domestic systems that utilise a twin vermidigester for primary treatment, a recirculating secondary treatment vermifilter, an optional recirculating tertiary treatment vermifilter and pumped surface irrigation distribution.

Pump-out tank and surface irrigation

Although in some circumstances a bell siphon could provide sufficient water pressure to irrigate drip lines, this section will focus on solar systems incorporating water pumps, solar panels and batteries, to provide a more versatile system that irrigates uphill or downhill of the treatment plant.

A solar pump-out tank requires a DC pump, a battery, a solar panel and a controller to switch the pump on and off:

1. Solar panel

A nominal 12 volt 40 watt panel is sufficient for most domestic pump-out tanks

Cost: Approx. US $70

2. Battery

Recommended: 12.8V 14Ah Lifepo4 battery with overvoltage and undervoltage protection

The Small Den battery available on Ali Express has:

Output voltage range: 10V-14.6V

Discharge cut-off voltage (V): 10 +/- 1V

Charge cut-off voltage (V): 14.6V

30A BMS, 4S2P (8x 32700 cells)

Cost: Approx. US $70

3. Controller

XH-M203/HCW-M203 Water Level Controller Pump Switch Module

A single water level controller is required, with a relay output capacity of 10 amps

Cost: Approx US $5

2x Water Level Sensor Right Angle Float Switches

Two switches are required, an upper water level switch and an under water level switch

Cost: US $5

4. Pump

The pump should not draw more than 10 amps (the capacity of the controller relay) and should exceed the head required for the irrigation lines.

Recommended: Seaflo 01 series 1100GPH Bilge pump


Flow rate 1130 GPH, Voltage 12v, Max draw 6.0 A , Head 4.5m, Outlet diameter 1-1/8"

Cost: Approx. US $25

5. Assemble the components

*Under construction*