Mary Ann Road, Galiano Island

Potable water supply 100% rainwater & Emergency Cross Connection to well water

This rainwater catchment system was designed for a home and B&B on Galiano Island, BC. The well water has extremely high levels of iron, magnesium, sulfur and salt, making it unusable. A seawater desalination system was considered as the capital costs are similar to a rainwater catchment system, but has a much higher operation/maintenance cost. The owners had a preference for natural vs. technical solutions as well as a large roof catchment area.

15,000 gallon cistern

System Features

• 50% ashphalt shingle & 50% flat torch-on roofing, 2,500 sq ft roof area, thus water quality challenge
• Small leaf traps & sealed standpipes to carry water under deck
• Catchment/transport pipe under decks incorporate debris pigtails & clean-out plugs
• First flush diverter rejects first flush of water over 3/4 mm (0.05 inch)
• Water pumped 400 ft (60 vert. ft) in shallow trench (winter drain back prevents freeze-up)
• Stored in 15,000 gallon cistern, 17'6" diameter x 10 ft tall (shown at left)
• Uses gravity flow from cistern to BioSand filter& 600 gallon day tank
• Electronics to control flows, protect pumps & limit amount of well water supply
• BioSand, particle filter and ultraviolet light disinfection system

Self-cleaning Leaf Trap

Pipe debris traps under deck

BioSand treatment system &
pressure tank