Alternative Irrigation
Frank Henning
Watershed Extension Agent
Sources, Definitions & Regulations
• Potable water (public vs. private)
• Preuse water
• Black water
• Gray water
• Condensate water
• Reuse or reclaimed water
• Stormwater
• State waters
Conventional Sources
of Water
- Public water supply system (municipal water)
system for provision of piped water to the public for
human consumption.15 connections, or 35 individuals
for ≥ 60 days/year. Subject to water restrictions.
- Private water supply system – usually supplied by ground
water (wells). < 15 connections and 35 individuals.
No permit, few restrictions.
- State waters - bodies of surface or subsurface not entirely
confined and retained on property of individual
-Permitted withdraws - average withdraws ≥ 100,000 gpd
in one month from surface or ground waters.
Preuse Water (unofficial term)
Unused potable water – water that is collected
while a user is waiting for tap water to begin
running hot or cold.
local governments may allow this water to be
used to fill toilet tanks or water plants.
Wastewater Sources
(alternative sources)
Reclaimed water (reuse water) wastewater that is highly treated, but
not potable.
Black water – wastewater generated by: water closets,
urinals, bidets, kitchen sinks & garbage disposals
Gray water – wastewater generated by water-using fixtures
and appliances, excluding water closets, urinals, bidets,
kitchen sinks and garbage disposals (purple pipe).
Florida’s Reclaimed Water Program
>1200 mgd
>600 mgd
Reclaimed Water Use
Onsite Wastewater Management
in Georgia (subsurface)
• 40%+ of housing units in
Georgia use on-site systems
for wastewater disposal
– 1,500,000+ units
– 50,000+ onsite systems
permitted annually in Georgia
50%+ of new homes built
• Georgia is typical for SE
states and other growth
regions
Gray Water
•
•
•
•
~65% of total wastewater
Low in organic material (less treatment)
May contain fecal bacteria, viruses….
Bad news - surface discharge requires a
NPDES permit
Graywater Workgroup
Recommendations
Outdoors
DHR regulations (Health Dept.)
Indoors
• International Plumbing Code, 2006
• Georgia State Minimum Plumbing Code
- Dec. 15, 2007 deadline for 2008 review by State
Codes Advisory Committee
- Gray water for flushing toilets and urinals
- Requires: Holding tank, filtration, disinfection,
backflow prevention, dye injection, purple pipe
- Local govt plumbing codes – adopt, amend, nothing
Graywater - Indoor Use
• Flushing toilets
– 26% of household water use (AWWA)
– Per capita consumption > 100 gal/day (EPA)
– Household of 4 could save 40,000 gal/year
Source: AWWA
Land Application of Wastewater
Conventional Drainfield
• Distribute wastewater
into the soil
• Temporary storage
• Little, if any, treatment
Combining Irrigation with
Onsite Wastewater Management
- DHR, Public Health Regs. (Co.Health Dept.)
- Manual for on-site sewage management systems
- Subsurface application of gray & black water
- Manual for on-site sewage management
- Engineered system
+
Pressurized Subsurface Drip
- Normally used for unsuitable soils
- Aerobic pretreatment (BOD<25mg/l
- Solid separation/filtration (TSS<30mg/l)
- Pump
- Minimum of 6” earth cover
- Subsurface drip irrigation
in the root zone
Household Water use (gray + black)
~ 400 gal/day (2800 gal/week)
~ 1 inch on ~4,500 square feet
Other Sources
Condensate water (use not regulated)
water that condenses on air conditioner coils
Stormwater (use not regulated)
The portion of rainfall that does not infiltrate
into the soil, or water that runs off impervious
surfaces
Water Ban Options
• Landscape Design
• Wastewater drip
• Harvest Condensate
• Harvest Rainwater