Off-color well water

[wbnethery3]

I have spent a lot of time searching online and found this forum to be among the best at providing answers to questions without fussing about "search the forum first". I have searched forums and cannot seem to see any situations that directly correspond to mine, but that may be a failure of my searching abilities. I'll describe it and please let me know what you think.

We live just outside Houston, and have a well which is our single-family home water supply. It was drilled in 2007 during construction of the home. The well is 353 ft. deep, submersible pump, sand formation. Per the driller's report, depth to water was 78 ft. below surface, pump bowl was 160 ft. deep.

Problem description - We have noticed from the beginning that the water quality was not "pristine". The initial conditions we observed were a slight sulfurous / rotten egg smell (H2S) which we had been previously warned about for wells in our area, as well as a slight amount of sediment. We consulted with the well driller and he assured me that if we flushed the well for a couple of days it would "clear up"... but it didn't. We filled a 40,000 gallon swimming pool and water quality never changed appreciably.

I installed a whole-home sediment filter and a fine-particle carbon filter after it. These are both off-the-shelf items from Lowe's (Whirlpool brand). The carbon cartridge completely eliminated the odor, and we couldn't detect any sediment in the house. The fill line for the swimming pool was taken directly after the well tank, and we could still smell the odor when adding water to the pool. There was also a noticeable tint of gray in the water to the house. This was most easily observed in our bath tub, which is white porcelain. It takes a large volume of water to realize that it isn't crystal clear, and it is not easily observed in any clear glassware. It could also occasionally be observed as a black residue on the toilet bowls where the water sits (not a ring, but a light patchy discoloration of the part of the bowl which is submerged).

Immediately prior to move-in, our driller chlorinated the well. Right after moving in, we had tests done on the water, to assure that it was sanitary (Coli-form bacteria and HPC). We also had samples tested for hardness (and used our pool testing equipment as well), and they confirmed our observations that the water was not "hard" because soap lathers quite easily. Have lab results but cannot find them at the moment. The well driller's report also states the water as "soft". We have not had the water tested since the first year. We chlorinated the well once more about one year after move-in, and have not had any concerns about the water from a health standpoint (i.e. no illnesses that we might tie back to bad water).

For lack of any other cause, I can only surmise that the Texas drought of 2011 seems to have brought about a change in our water quality. We have noticed that the sulfurous odor appears to be gone, and in its place I now detect a "bicarbonate" smell (for lack of a better description). The water straight out of the well is fizzy (not soda-pop foamy, but definitely some sort of dissolved gas). It has a faint but distinct odor which is not unpleasant, but definitely not what I would call "normal". We found over this past summer that we were getting reddish-brown solids coming out of our hot water heater, which gunked up our washing machine and bath tub. I flushed the tanks of the water heaters, which was the first time it had been done since we moved into the house.

We are now seeing that the gray tint is darker, and have really come to a point that we are concerned about the safety of the water for consumption. I had recently installed cartridge filters which don't have carbon, since the odor seems to be a non-issue. After getting complaints from my wife about the appearance of the water, I just today switched back to a carbon sediment filter (25 micron) and a carbon secondary filter (2 micron). The water is still dark. It seems to be a dissolved mineral, however, when draining the tub I notice what appears to be fine particles left behind. They remind me of the material I observe left on the sandpaper when wet-sanding the steel axles on my sons' pinewood derby cars... so if it's smaller than 2 micron, I don't know how to filter it out.

Any advice on possible solutions would be greatly appreciated. I do plan on calling a water treating specialist, but I fear getting a hard-sell on a water softener just because those guys only have one trick up their sleeves.

[VAWellDriller]

I would try flushing again, for a long period of time. It sounds like this was drilled mud rotarty, and if that's the case, what you are seeing could still be trace drilling fluid (which gets turned gray from gray clay formations). I drill mud rotary and install screened gravel packed wells, and this is a problem sometime when the well makes a lot of water or the driller doesn't spend enough development time. For example, I may install a well that is capable of pumping 200 gpm, and I airlift develop at only 100 gpm due to friction loss and other constraints of the airlift,then I put a 10 gpm pump in and hook it to a house. There may be large sections of screen that don't get developed, since the capacity of the well is so high, and over time, the drilling fluid is slowly broken down and tints the water. There are a couple solutions; heavy, heavy flushing, days or weeks at the highest rate you can. If this doesn't work, pulling the pump and re-developing the well by airlift or jet cleaning should get it. I have also seen this a problem if the driller didn't grout the well properly or gravel pack the screen properly. As far as the sulphur, we have that here too, and it seems to come and go for no reason at all. A confined aquifer is not affected by drought, so the water quality changes you are seeing are coincidental.

[wbnethery3]

Thanks for the comments. I'm surprised the well would still be "developing" after 5 years of use. The driller report did say it was drilled mud rotary, and showed the Haliburton annular seal method, with first interval "from 0 to 330 ft. with 24 (#sacks and material)", k-packers 325 ft., all of which means nothing to me. It also showed a jetted capacity to be estimated at 100+ gpm. Would drilling mud be able to pass through a 2 micron filter cartridge? The time the driller spent from start to finish was 3 days, so I don't know how much time he put into developing it.

[VAWellDriller]

The high yield is what I expected...... 3 days is plenty of time to do it right. What you have isn't how I would install a well, but it may be customary down there. You well screen is not gravel packed, it's naturally packed with formation sand. The grout job sounds good and makes sense for what they have done. I would consider getting them of somebody to come out and blow the well again....that's probably the fastest way and best chance of getting it cleared up. I wouldn't think much would pass throught the 2 micron filter, but I guess it's possible.

[wbnethery3]

Update on the situation -

Did more troubleshooting today. I first found that the filter in my GE refrigerator was good enough to filter out what the carbon 2 micron filter wouldn't. The ratings for the fridge filter are 0.5-1 micron, so I went to the store and bought a cartridge with that rating. Unfortunately, it was an under-sink cartridge with very low flow capacity. As soon as I installed it in the whole-house filter housing, it flowed very little before stopping altogether.

However, in the process of doing all of that, I found that the well tank (Pentair SP-series fiberglass) is leaking near the top. The pressure has been surging a modest amount the last few days, which corresponds to the appearance of the noticeably darker water. I flushed the well for about 30-45 minutes through a 3/4" PVC connection to my pool fill line, and then immediately sampled the water. Sure enough, the water is clear! This appears to be a problem of the tank failing and contaminating the water. I've read about this possibility, but the leaking water from the top really makes it my lead case. Flushing long enough to get rid of the immediate contaminant inventory allows me to sample essentially directly what is coming up from the well. I don't have a valve between the wellhead and the tank, or I would do it that way just to confirm.

Is it surprising that a fiberglass tank would fail after only 5 years of residential service? This seems too quick. Sadly, it's a 5 year warranty and we've been in the house 5 years and 2 months. Thoughts?

[Texas Wellman]

I was burned on a fiberglass tank last week that failed after exactly one year. I have stopped using them for the most part.

Your well seems to be par for the course for our area. Remember, your driller can only get you the water that's already there, he cannot control the quality of the water in the ground.

I would recommend either going back with a Well X trol tank or a galvanized tank. If your well has an air-maker than go back with the galv. tank for sure. Galv. tanks are very popular in this area and most people say they keep the smell down and help with the taste of the water.

[wbnethery3]

Problem solved
We have a new tank and the water quality is now back to its previous condition after copious amounts of flushing. Our driller sold us a different brand tank (FlexLite FLS120D by Flexcon). It appears that because the tank was "water logged" (i.e. no air bubble) and the pump was short-cycling, fine sediment was shaken up from the bottom and carried up the well. We are just a bit frustrated that the tank would fail so soon. It only has a 5 year manufacturer's warranty, but our driller says he has a large number of them he won't sell and the company won't warranty. Just wondered if anyone else has had problems with Wellmate SP-series tanks by Pentair.