Water Quality

Acidic Well Water: What Your pH Result Means

Acidic water is one of the most common findings in well tests across our area. Penn State Extension estimates that about 60% of private wells, springs, and cisterns in Pennsylvania have corrosive water, and the shale bedrock found in parts of southeastern Pennsylvania is known for it. Low pH isn’t harmful to drink by itself, but it quietly eats away at your plumbing and can put copper and lead into your drinking water.

What pH measures

pH measures how acidic or alkaline water is, on a scale from 0 to 14. A pH of 7 is neutral. Below 7 is acidic, and above 7 is alkaline. Your report compares your result to a recommended range of 6.5 to 8.5.

The scale is logarithmic, so small differences matter. Water at pH 6 is 10 times more acidic than water at pH 7, and water at pH 5 is 100 times more acidic. A result of 5.5 is well into corrosive territory, even though the number looks close to the guideline. If you’re buying with an FHA or VA loan, the lender’s acceptable range is narrower: 6.4 to 8.0.

Why low pH matters

Acidic water dissolves metal from your plumbing. The common signs are:

Blue-green stains in sinks and tubs, from copper dissolved out of the pipes.
A metallic or bitter taste, especially in the first water out of the tap in the morning.
Pinhole leaks in copper pipes over time.

The bigger concern is what you can’t see. Corrosive water can dissolve lead from the solder used to join copper pipes. Lead solder was common until it was banned in 1991, so any home built before then with metal plumbing likely has some. Lead has no taste or color and can only be detected by testing, and it is especially harmful to children. A Penn State survey found that about 20% of private water systems in Pennsylvania had unsafe lead levels.

If your pH is low, ask about a first-draw lead and copper test, which samples the water that has sat in your pipes overnight. Our Chester County Complete package doesn’t include lead, but Chester County Complete with Lead and the FHA/VA package do. The FHA/VA package tests both a first-draw sample and a flushed sample: if lead shows up only in the first draw, the source is the plumbing, not the well. None of the packages test for copper.

A note on how pH is measured

pH can change once water leaves the well, so the official method calls for measuring it within 15 minutes of sampling. Samples delivered to a lab are usually tested hours later, and your report may note that pH was analyzed outside that holding time. The result is still a good indicator, but before buying treatment equipment, it’s worth confirming with an on-site pH reading.

What to do about acidic water

Flush before drinking. Metals build up in water that sits in the pipes. Running the cold tap for about a minute before drinking, especially in the morning, draws fresh water and lowers copper and lead levels. It’s a simple habit, not a long-term fix.
Acid-neutralizing filter. A tank of calcite (crushed limestone), sometimes blended with magnesium oxide for lower pH, raises the pH as water flows through. It’s the most common fix. It adds some hardness to the water, and the media needs refilling every few months.
Soda ash injection. A small pump feeds a soda ash solution into the water. It suits very acidic water and doesn’t add hardness, but it needs more maintenance.
Plastic plumbing. Replacing copper with approved plastic pipe removes the source of copper and lead, though the rest of the system may still be affected.
Point-of-use filter for lead. If lead is found, a reverse osmosis unit or a filter certified for lead at the kitchen tap protects drinking and cooking water.

If you’re also treating iron or using a softener, the order of the equipment matters. A treatment professional can design the full system.

The bottom line

Low pH is common in our area and easy to overlook, because the water usually looks and tastes fine. It’s worth taking seriously because of what it does to your plumbing and the possibility of lead. If your pH is below 6.5, consider a lead and copper test, flush your taps in the meantime, and talk to a treatment professional about neutralizing the water.

Chester County Home Inspections provides water quality testing throughout Chester County and the surrounding counties. We collect samples using EPA protocols and deliver them to a PA-DEP certified laboratory. If you have questions about your results, get in touch.