Transcript Is Your Well Water Safe?

Is Your
Well Water Safe?
by
Bob Schultheis
Agricultural Engineering Specialist
Missouri
Water Supply Statistics
890,000 Missourians on private water
supplies
 86% on drilled wells
 300,000-350,000 active wells
 10,000-20,000 new wells drilled annually
 One abandoned well or cistern for every
80 acres of land (DNR estimate)

– Webster Co. = 4,700+ wells over 379,000 ac.
What is Coliform?

Coliform bacteria are used as indicator
organisms to test for contamination of
drinking water.
– >1 coliform = “Unsatisfactory” in DOH tests
E. coli is a member of the coliform family
and is commonly found in raw sewage.
 E. coli is responsible for many
health-threatening diseases.

Coliform-Associated Diseases
Cholera
 Typhoid
 Salmonella
 Shigella
 Staphylococcus
 Hepatitis A, B, C
 Polio
 Viral Gastroenteritis

1994 Coliform Detection Study
May to Nov. 1994 well survey
 9 states- Illinois, Iowa, Kansas,
Minnesota, Missouri, Nebraska,
North Dakota, South Dakota, Wisconsin
 41.3% tested positive
 E. coli detects averaged 11.1%
 Missouri E. coli detects - highest at 22.6%

Sampling Results
Private Wells
3
4
2
1
100
5
6
80
60
40
20
0
Area 1 Area 2 Area 3 Area 4 Area 5 Area 6 Sp Area
TC
EC
NO3-N
Factors Contributing to
Coliform Detects
Improperly constructed wells
 Poorly maintained wells
 Ineffective on-site sewage systems
 Proximity to livestock feeding operations
 Karst geologic formations

Nitrates

Nitrate detects are relatively low although
not uncommon. (up to 16% of samples)
– >10 ppm NO3-N = “Unsatisfactory”

Sources
– Livestock facilities (esp. abandoned ones)
– N & P fertilizer in excess of crop removal
capability
– Failing septic systems
D.O.H. Water Quality Survey
August 1999
Webster County
“gridded” for
random sampling
 61 participants

D.O.H. Water Quality Survey
August 1999 Results - Webster County
Private wells
testing positive
for coliform bacteria
44%
Sewage systems
with open discharge
& surfacing effluent
28%
Soils in Webster County
79% rated “severe” for pollution potential
 21% rated “moderate”
 0% rated “slight”

“Losing” stream
Solution
Channel
What’s Wrong with this Well?
Ways to Reduce
Well Contamination
1

Soil blanket (5+ feet thick) is good filter

Elevation = keep above pollution sources

Distance = 200+ feet horiz. separation

Grout well with neat-cement or bentonite
clay by state-certified well driller

Use approved sanitary well cap

Rehab. poorly constructed wells
Ways to Reduce
Well Contamination
2

Plug abandoned wells & cisterns

Repair/move/replace failing septic systems

Apply fertilizer & animal manure according
to soil test & manure test

Repair/upgrade animal waste facilities

Install containment for fuels & pesticides
Ways to Reduce
Well Contamination
3

Don’t dump anything into sinkholes

Use grass buffer strips (50+ feet wide)
as filters around sinkholes

Promote community awareness of risk

Shock-chlorinate active wells after any
plumbing repairs
Shock-Chlorinating Your
6-inch Diameter Well 1

Remove well cap or unscrew vent pipe
Newer wells
Older wells
Shock-Chlorinating Your
6-inch Diameter Well 2

Mix chlorine & water in
bucket. Pour into well
– Liquid bleach @ 1 pint
per 25’ of water depth, or
– Chlorine tablets @ 0.5 lb.
per 150’ of water depth
Circulate water back down well
 Load chlorinated water into
plumbing system

Shock-Chlorinating Your
6-inch Diameter Well 3
Let chlorine water stand in
system at least 12 hours
 Flush system with water,
starting outside
 Retest for bacteria after 7-10 days

– $10 cost; DOH has sterile sample bottle
– Keep sample cool & dark, get to lab in 6 hours

Keep test results with important papers
University Information
Guides Available
WQ100 Water Testing: What to Test For
 WQ101 Understanding Your Water Test

Report
 WQ102 Bacteria in Drinking Water
 WQ103 Nitrate in Drinking Water
 WQ104 Understanding Home Water
Treatment Systems
Questions???
Robert A. (Bob) Schultheis
Agricultural Engineering Specialist
Webster County Extension Center
800 S. Marshall, P.O. Box 7
Marshfield, MO 65706-0007
Voice: 417-859-2044
Fax: 417-468-2086
E-mail: [email protected]
Website: http://outreach.missouri.edu/webster