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Madison / Union County · Plain City Water Department

Plain City, Ohio Water Quality Report

Hardness levels, common contaminants, and what Plain City homeowners should know about their tap water — updated August 2026.

Plain City Water at a Glance

Hardness
16 gpg
274 mg/L
pH Level
7.1–7.5
Neutral range: 6.5–8.5
Chlorine
0.4–0.8 mg/L
EPA limit: 4 mg/L
TDS
240–310 mg/L
Total dissolved solids

Water Hardness Meter — Plain City

At 16 grains per gallon, Plain City water is classified as Very Hard. For context, anything above 10.5 gpg is considered hard; Columbus-area water typically runs 15–18 gpg.

Soft (0)Moderate (7)Hard (11)Very Hard (18+)
16 gpg — Very Hard

Common Water Problems in Plain City

Very hard water scale

Plain City water at 16 gpg is very hard. Scale builds up quickly on water heaters, dishwashers, and plumbing — reducing efficiency and shortening appliance life. The Madison/Union County limestone geology is the primary cause.

Iron staining risk

Plain City area water can carry iron levels approaching the EPA secondary standard of 0.3 mg/L. Homeowners sometimes notice orange or rust-colored staining on fixtures, laundry, and toilet bowls.

Agricultural runoff

Plain City sits in a heavily farmed area of Madison and Union Counties. Nitrates and herbicide residues from agricultural runoff can enter the water supply. An RO system provides critical protection for drinking water.

Dry skin and hair

At 16 gpg, Plain City water strips natural oils from skin and hair. Residents often notice dry, itchy skin after showering and dull hair — both direct effects of very hard water.

Iron Level: 0.1–0.35 mg/L

Iron above 0.3 mg/L causes orange staining on fixtures, laundry, and appliances. The EPA secondary standard is 0.3 mg/L. If you notice rust-colored stains or metallic taste, a dedicated iron filter may be needed alongside a water softener.

Iron filter options

Plain City Water FAQs

How hard is Plain City, Ohio water?

Plain City water tests at approximately 16 grains per gallon (gpg), or about 274 mg/L. This is classified as very hard. The area sits on limestone-rich geology spanning Madison and Union Counties, which naturally elevates hardness minerals.

Does Plain City water have iron?

Plain City area water can contain iron levels approaching the EPA secondary standard of 0.3 mg/L. Some homeowners notice orange staining on sinks, toilets, and laundry. A free in-home water test will confirm your exact iron level.

Is Plain City water safe to drink?

Plain City water meets all EPA Safe Drinking Water Act standards. However, given the agricultural activity in Madison and Union Counties, many homeowners add a reverse osmosis system for extra protection against nitrates and other runoff contaminants.

What water treatment do Plain City homeowners need?

Most Plain City homes benefit from a whole-home water softener to address the 16 gpg hardness, plus an under-sink reverse osmosis system for drinking water. Homes with visible iron staining should also consider an iron filter installed before the softener.

Know exactly what's in your Plain City water.

Our free in-home water test gives you precise numbers — hardness, iron, pH, TDS, chlorine — at your tap. No obligation, no pressure.