Low pH and Acidic Water in Northwest Arkansas
Acidic water is water with a pH below about 6.5. It is not dangerous to drink at the levels typically found in household wells, but it is corrosive, and it attacks your plumbing from the inside — dissolving metal out of your pipes and into the water you drink.
That is the part that makes it worth fixing rather than tolerating.
Common symptoms
People describe this problem to us in these ways. You may recognise several, or only one.
- Blue-green staining in sinks, tubs or around drains
- A metallic or bitter taste
- Pinhole leaks in copper pipe
- Corroded fittings, valves and water-heater components
- Rust-coloured staining from steel pipe or fittings
- Fixtures wearing out unusually quickly
Potential causes
Naturally soft, low-mineral groundwater
Water with little dissolved mineral content has little buffering capacity, so it stays acidic. Some shallow Ozark wells produce exactly this.
Rainwater infiltration
Rain is naturally slightly acidic; where it reaches an aquifer quickly, as it can in karst terrain, there is less opportunity to pick up neutralising minerals along the way.
Dissolved carbon dioxide
Forms carbonic acid in water. A common contributor in groundwater.
Decaying organic matter
Water passing through organic-rich soil can pick up acidity.
Cistern or rainwater collection systems
Collected rainwater is typically acidic and low in minerals until treated.
This one requires testing to confirm
pH is quick and cheap to measure, and the blue-green staining is a strong visual clue — that colour is dissolved copper.
There is a second test worth doing where acidic water is confirmed, particularly in a home built before 1986 when lead solder was still permitted: a first-draw sample tested for lead and copper. The same aggressive water that dissolves copper can dissolve lead from old solder joints, and unlike copper, lead leaves no visible stain to warn you.
Treatment technologies commonly used
Which of these is right depends on what your water actually measures. These are the technologies genuinely used for this problem, not a list of everything we sell.
Acid-Neutralizing Systems
The standard treatment: passing water through calcite or a similar medium that dissolves slowly and raises pH.
Water Testing
pH, alkalinity, hardness, copper and lead together give the full picture.
Whole-House Water Filtration
A neutralizer is a whole-house device and usually sits first in the treatment train.
Reverse Osmosis Systems
For drinking water specifically, where metals are confirmed at the tap.
Questions we are asked about this
Is acidic water dangerous to drink?
The pH itself is not the concern at the levels found in household wells — many everyday drinks are considerably more acidic than acidic well water. The concern is what the water dissolves out of your plumbing on the way to your glass, particularly copper and, in older homes, lead.
What causes pinhole leaks in copper pipe?
Acidic or otherwise aggressive water gradually thinning the pipe wall from the inside until it perforates. Repeated pinhole leaks in different places is a strong sign of a water chemistry problem rather than bad luck, and repiping without correcting the water means starting the clock again.
Does a neutralizer make water hard?
To a degree, yes. Calcite works by dissolving calcium carbonate into the water, which raises pH and also raises hardness. On water that was already hard, a softener after the neutralizer is a common pairing.
Can I just add something to my water heater?
No. pH correction has to happen at the point of entry, before the water reaches your plumbing, because the plumbing is what you are protecting.
We work across Northwest Arkansas
City water and private wells, in Benton, Washington, Madison and Carroll counties.