VAMWON Notes from the Field are the stories of the questions
I’ve encountered as a volunteer with VAMWON. The Virginia Master Well Owner
Network (VAMWON) is an organization of trained volunteers and extension agents
dedicated to promoting the proper construction, maintenance, and management of
private water systems (wells, springs, and cisterns) in Virginia. The
Cooperative Extension Services in Virginia manages the program and have
numerous publications and fact sheets that can help homeowners make educated
decisions about their drinking water. The VAMWON volunteer or Agent can help
you identify problems with the water system and provide information on
suggested treatments options and other solutions, but there are times all we
can offer is a framework on how to gather information and think about your
problem. You can
find your VAMWON volunteer neighbor through this link by entering your county
in the search box.
I regularly receive contacts from people and sometimes all
we do is talk about wells. I collect data from all the contacts to increase my
knowledge, get current prices of having a well drilled and hear about which
well drillers people were satisfied with. This is the story from Lloyd.
“I live in Fort Valley
VA, about an hour West of Haymarket. I have had this home for about 3
years and recently ran into a problem with my well water turning very cloudy,
almost muddy. The well for the house is about 40 years old and from what
I know from a neighbor is somewhere between 225 and 300 feet deep. When
it was drilled they rarely used much of a casing and apparently the pump and
all tubing is original. I had no problems with the water at all
until recently. “
At this point I would like to interrupt his story with some
observations. First this is a drilled well. Drilled wells are typically more
than 100. In Virginia well drillers are required to file a drilling log with
thecounty and comply with drilling regulations since 1992. If the well was
drilled before 1992 you have to think that sooner rather than later you will
have to replace not only the well
components, but also depending on your geology the well. While many wells
will last decades, it is reported that 20 years is the average age of well
failure. Pumps, pressure tanks, switches and other equipment tend to last about
15 years or so. Mechanical equipment has a limited life and will fail sooner or
later. Well casings are subject to
corrosion, pitting and perforation.
A second note is that just because your neighbor’s well is
at 225-300 does not mean that your well is. My well is at 150 feet below grade
and my nearest neighbors are at 250 and 175 feet below grade. On our county
land the wells are drilled from 150 to 450 feet below grade. (Yes, I looked up
the well completion report for every home in my surrounding 360 acres.) Back to
Lloyd’s story.
“In July I started
construction of an addition to my house which required excavation. The
fill was placed on the side of a hill on our property, perhaps 50 feet from the
well. A few days later, we had 4” of rain in a very short period of time
and our water was muddy for several days. I chalked it up to infiltration
from the water mixing with the fill and penetrating the water table by getting
around the casing. A few weeks ago we had a quick 2” rainfall and once
again we had cloudy water (unsuitable for drinking) for a few days. But I
had the problem again this week and we had no rain. I did do some power
washing and the water went down a drain which drains who-knows-where but there
really should not have been enough of this water to stir things up. If it
was infiltration it should clear up in a day or two, but I think this time
could be different.
Prior to the
construction I had my water tested to see if I would benefit from a water
softener. I was told my water was pretty good and there would be little
benefit to adding a water conditioner. Given the age of the well and
equipment I realize it could be about anything, particularly the casing (or
lack thereof) creating a problem. I am a bit gun shy about calling a well
driller in since obviously he will want to re-drill the well, replace all the
equipment and the connection to the house which would involve pulling apart a
very expensive patio which sits over the pipe (or hose) coming from the
well. It won’t matter if that is the real problem. So do you have
any recommendations for someone to call who might be a bit more impartial about
diagnosing the problem?”
I responded:
You are right, given the age of the well and the complete lack of information
on construction, geology and yield it could be anything. Not all well drillers
will immediately suggest a new well if your well is functional (is not going
dry or collapsing), but some will indeed. You are really going to have to get
help on the ground where you are. I would suggest paying for a service call
from more than one well driller after talking to the health department. What I
can tell you is that your problem may be a geological one.
Massanutten Mountain in the Shenandoah Valley of Virginia is
in the Valley and Ridge regional aquifer system. The Valley and Ridge regional
aquifer systems are within the Valley and Ridge Physiographic Province. The
carbonate rocks in the Valley and Ridge where you are have unique hydrogeologic
features like karst topography, solution channels, and caves. Ground water in
the carbonate rocks of the Valley and Ridge flows (1) in the regolith
(alluvium, colluvium, and residuum); (2) along fractures, joints, and bedding
plane partings in the bedrock; and (3) in solution channels and cavities
(caves) formed by the dissolution of carbonate minerals.
It is possible that your problem is caused by a solution
channel that has formed in the karst terrain. This could have been created by
time, water flow or the weight of the excavating equipment and soil piled up on
the ground. If this is the cause the filtration and potentially secondary
treatment is the solution not a new well and the water might just begin to
clear up on its own. However, your well casing could be collapsing from rust, you
could be pumping Virginia clay to the surface or you could have a significant
amount of surface infiltration from the dirt piled on the hill and being
mobilized by all the rain.
Well production and a careful analysis of the water (not one
of the free tests to see if the water is hard by test strips) can help you
determine if your well is failing or has been impacted by the creation of a
channel or cavity or if you have surface infiltration. Surface infiltration
would be characterized by the presence of coliform bacteria. However, the
creation of a solution channel in karst terrain could bring surface water into
contact with the ground. A Ground penetrating sonar can identify voids (that is
not always available in small towns it is used typically for commercial
projects and re-development), but you need to figure out what is going on with
your well.
Start with the health department in your county. Here in
Prince William we have practiced solutions to many of our typical problems.
Talk to the health department, talk to at least two well drillers, do a
complete water analysis on your well. Samples should be analyzed for at least:
iron, manganese, nitrate, lead, arsenic, fluoride, sulfate, pH, total dissolved
solids, hardness, sodium, copper, total coliform bacteria and E. Coli bacteria.
The bacteria could identify a surface infiltration, the pH an acidic condition
that would over time impact the well casing, etc...It would also be helpful to
test the yield on your well to make sure that your well is not going dry. Also,
wells often have fine mesh filter socks that fit tightly over the slotted
screen in a well and are designed to allow water to pass through while
preventing fine sand and clay from entering the well screen. These days they
are made of knitted polyester, which is more inert and resistant to degradation
than nylon which was used in the past. Remember, if you pull the pump, you
should replace it. No use paying to pull a pump from the ground and then
putting an old piece of equipment back in. Good luck and let me know how you do,
“Thank you so much for that detailed response. I suspect your solution channel explanation
caused by the full is very likely. The water is slowly clearing up.“
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