Well contamination and treatment

I got a well report for a property I've been looking at, and 3 things stand out as exceeding the maximum contaminant levels.  I've never dealt with wells or water contamination before so I thought I'd seek the wisdom of the permies hive mind.  Should this stop me from buying an otherwise great property?  What are the options for treating this?  Here's what I've got, thanks in advance:

Iron - .88 mg/L
Conductivity - 934 μS/cm
Total Coliform Present - 1046.2/100ml (non E. coli)

I went and looked up the original well report, it had 1.25 gal/min with 158.8ft drawdown after 2+ hours, full recover in 12 (hours? minutes?)

water
just might be king over bread as the staff of life
its much easier to deal with if your in an area that does not freeze hard in winter.
I know in Florida several years ago a whole lot of people on wells started going with whole house RO systems because a lot of the state has such bad water and salt water intrusion.

have you seen the well head? we had a test after our water started running cloudy after some big rain in the spring, and we had pretty elevated coliform numbers. it turned out that our well head was too low so a lot of water on the ground could get in the top. after we had it extended up above ground level (like it was supposed to be anyway) it tested good.

Greg, I remember touring the property and finding the well head.  I'm pretty sure it was above grade, I'll double check next time I'm out there.

You piqued my curiosity so I went looking ... my sources are scattered all over the world.  I bet some state or county level gov unit in WA has some other numbers...

Basically, any amount of coliform renders the water undrinkable.  Iron seems to be well above the EPA suggested "cosmetic" limit of .3 mg/l but well below one state's medical limit of 2.5 mg/l (North Carolina). Conductivity - a measure of salts for those at home - is into the second category level (.  https://mrccc.org.au/wp-content/uploads/2013/10/Water-Quality-Salinity-Standards.pdf  says that water " Can be consumed by humans, although most would prefer water in the lower half of this range (800-2500) if available"

So the issue is coliform .... https://www2.gnb.ca/content/dam/gnb/Departments/h-s/pdf/en/HealthyEnvironments/water/Coliforme.pdf suggests the next step is to identify the source.  You may be able to clean the source out, dig a deeper well, or filter.

Interesting info Eliot, the well is 180 ft deep but the land is 75 ft above sea level and about a mile and a half from the bay.  I wonder if that means the saltiness is unavoidable.

Not sure if this is popular with this community, but when we moved into our new home they bleached the well to knock out the coliform bacteria issue. We also have an in-line UV treatment thing, and so long as that never turns off we should be ok. Options for Kyle, maybe?

Brian I think chlorine treatment would be okay as a one time deal.  I'd make sure to purge it out and get that water off my property.

Draining the pipes was a PITA, but the end result was good. We emptied the water into our gravel driveway, can't let it go to the septic tank.

Does the UV light turn off automatically when power to the pump is switched off?  I used to do large scale aquatic habitat and we did that so the UV light wouldn't melt it's housing.

I don't believe it does. It has a counter on it for days until replacement, leading me to believe it stays on 24/7 (counter goes down a day per day).

I think the saltiness is probably a function of ocean proximity - and is really not a problem.   I'd suggest that the salinity won't be a problem for fixtures, pipes, etc but you might want to have an RO system at the sink for drinking water and some kitchen functions (ice, canning, kombucha).  That's a decision to make down the road.

I'd agree with Brian & Kyle on the bleach ... bleach might be nasty but balanced against the $ and  carbon footprint of digging a new or deeper well, it fares very well.  But it seems like some determination on the source is important to make sure the bleach goes in the right place and sufficient volume.

Thanks guys, I'm thinking the contamination is pretty easy to solve, home RO systems are relatively cheap.  The low flow and high drawdown are what are concerning me now.  I'm hearing the whole area is having issues.

I dealt with salt water intrusion for decades and the longest a new under sink RO lasted was less than a year and appliances and brass and bronze fixtures only lasted maybe 5 years at the most. but that was my experience with water that had about 1500ppm I think it was. You might just look into one of those whole house RO systems I think a commercial model is about $5000 with a 500 gallon tank but they can be pieced together for much less. its put together kind of like one of those water machines that you put quarters into.

Brian Holmes wrote:I don't believe it does. It has a counter on it for days until replacement, leading me to believe it stays on 24/7 (counter goes down a day per day).

yeah, we have one of those, and it will heat up the water that stays in the little uv tank a bit, but nothing scary. the cold tap will run slightly warm for a bit if it’s been awhile.

Shock treatment with a bleach solution at appropriate concentrations is effective and IMO does no lasting harm. All the wells I have seen need it on occasion.

Kyle.   Your water quality issues are not insurmountable.   Have you located a well log for the well that describes the geology?  

I doubt there would be a salt water intrusion problem, for a couple of reasons,  a low yield aquifer (1.25 gpm) would not be as susceptible as a higher yield aquifer that has more hydraulic communication with the estuary you mention, also 920 uS would not be that indicative of seawater intrusion...most seawater is over 40,000 uS.... chloride levels would also be very high.  

Coliform is only an indicator of bacteria in the groundwater, the lab should have also checked to see if e.coli is present.  If the well has not been used for a long time and surface leakage that found a way in and could be the source. Bacteria is common in near surface soils and in shallow groundwater (<25 ft below ground surface).  Sealing the well head and shock chlorination may take care of the problem.  If not a chlorination or UV disinfection could be used.   At <2 gpm you will probably be pumping to a storage cistern and a inexpensive pellet chlorinator could be fitted.  UV systems alcan problematic with high iron groundwater unless you remove the iron first.

The iron levels you report are not that high.  A simple ion exchange water softener will drop out these iron levels and manganese too.

Higher a reputable well service contractor to redevelop and chlorinate the well and then purge it before collecting new lab samples.  Then take the results to a knowledgeable water treatment contractor ...if needed.  Do this as a contingency to purchase and definitely before committing to any new construction.

Good luck.