A homeowner in Lothian called us after noticing blue-green staining around every faucet, drain, and toilet in the house. They had also discovered two pinhole leaks in copper supply lines in the past year — one under the kitchen sink and one in the basement. A neighbor had mentioned that acidic water was common in the area, but the homeowner had never had their water tested. They were concerned about the cost of continued pipe repairs and wanted to understand what was causing the problem.

We tested the water at the tap and at the pressure tank. The pH reading was 5.9 — significantly acidic. Water with a pH below 7.0 is corrosive to copper, brass, and galvanized steel. At pH 5.9, the water was actively dissolving copper from the pipes, which is what causes the characteristic blue-green staining (copper carbonate deposits). The two pinhole leaks were consistent with this level of corrosion. We also tested for iron (1.2 ppm — moderate), hardness (18 GPG — very hard), and total dissolved solids. The primary issue was pH — everything else was secondary. Anne Arundel County well water from the Aquia aquifer commonly tests in the 5.8–6.4 pH range, and this home was at the lower end of that range.

1. 1Tested water at tap and pressure tank: pH 5.9, iron 1.2 ppm, hardness 18 GPG
2. 2Confirmed two existing pinhole leaks in copper supply lines — repaired both before treatment installation
3. 3Sized calcite acid neutralizer: 1.5 cubic feet of calcite media for the household flow rate
4. 4Installed Fleck 2510 SXT control valve with automatic backwash cycle (every 3 days)
5. 5Installed bypass valve and union connections for future media replacement access
6. 6Plumbed neutralizer on the main supply line, upstream of the pressure tank
7. 7Tested pH at the tap after installation: 7.3 — within the ideal 7.0–7.5 range
8. 8Documented before/after pH readings and explained the annual media top-off schedule

The pH at the tap tested 7.3 after installation — a full 1.4 pH point increase. The blue-green staining will fade over the next few months as the corrected water rinses through the plumbing. No new pinhole leaks have developed in the six months since installation. The homeowner now has a water treatment system that protects the entire plumbing system — pipes, water heater, fixtures, and appliances — from acidic corrosion. Annual calcite media top-off is the only maintenance required.

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