INNOVATIVE PUMPING OFFERS HORIZONTAL GAS PIPE DEWATERING SOLUTIONS
A West Coast landfill called on Blackhawk Technology
Company to dewater remote gas wells no longer served
by electric or pneumatic power.
The closed Class D site includes 6-inch vertical wells
to depths of 100 feet with a 1¼-inch gas discharge.
More challenging has been dewatering near-horizontal
side-slope trenches in the closed section of the landfill.
Some customizing and experimenting with Blackhawk
Apollo™ solar piston pumps have been most effective.
A NEW WAY TO PUMP
The landfill purchased three Apollo units with variable
solar charge controls and 180-watt solar panels for
dewatering three canyon gas wells. The Apollos
successfully dewatered all three wells while running only
during daylight hours at roughly 1 gallon per minute.
The site engineer moved one pump to a gas-well trench
in the same landfill and increased the flow to 5 gpm
by increasing the foot-valve diameter and installing an
experimental high-speed motor and gear configuration.
Pumping virtually horizontally, with a 36-inch-diameter
casing and pump placement at 300+ feet, the Apollo
removed 575,000 gallons in one year.
The second Apollo pump was moved to a trench on
the landfill’s front face. The engineer added a 240-watt
panel, a 15M controller and 4 marine batteries to pump
at 2.5 gpm with a larger than standard foot-valve
assembly. This Apollo configuration maintains the
trench in dewatered status, running 24 hours a day
but needing a reset after the occasional storm.
ADAPTABLE SOLUTIONS
In 2013, the landfill purchased two additional Apollo
pumps with high-speed motors and augmented control
boxes. They were installed on the front face next to
the pumps with battery backup. The new pumps have
drawn down liquids in the trenches while pumping
during daytime but initially did not maintain consistent
gas flow. A battery backup system for the high-speed
Apollos was designed to close the gap.
The engineer was pleased he could run five horizontal
side-slopes and one vertical well on one header for gas
recovery. The customized pump drivers remain in use.
