Richardson Water Is Very Hard — Here's What It Costs You Each Year

Why Is Richardson Water So Hard?

Richardson sits at 11.8 GPG (202 ppm), which puts it squarely in the “very hard” category. That’s not a fluke or a seasonal blip; it’s baked into the water itself. The city draws from surface water sources, and those sources pick up hardness the old-fashioned way: by flowing over and through mineral-rich ground before ever reaching your tap.

Here’s the plain-English version of what’s happening. Rainwater is naturally soft and slightly acidic. As it runs over the ground and into the reservoirs and lakes that supply Richardson, it comes into contact with limestone and dolomite formations common across North Texas. Those rocks are essentially compressed calcium and magnesium carbonate. Water is a decent solvent, and slightly acidic water is an even better one. So it slowly dissolves those minerals right out of the rock, the way hot water dissolves sugar out of a tea bag. Calcium and magnesium ions end up suspended in the water, and that’s the whole story of hardness. The longer the water sits in contact with those formations, and the more ground it covers, the more mineral load it carries.

The USGS classifies anything above 7 GPG as hard and anything above 10.5 GPG as very hard. At 11.8 GPG, Richardson is running nearly 62% above the national average of about 7.3 GPG. You’re not imagining it when your soap doesn’t lather well or when spots show up on freshly washed glassware. That’s dissolved rock, plain and simple, and it’s doing exactly what dissolved rock does.

It’s also worth understanding what hardness is not. The EPA does not regulate hardness as a health hazard. It’s listed only as an aesthetic Secondary Maximum Contaminant Level. That means the water is perfectly safe to drink; it just happens to be carrying a heavy mineral load that affects how it behaves in your home.

How Richardson Compares to Nearby Cities

Richardson’s 11.8 GPG reading puts it on the higher end for the Dallas-Fort Worth metroplex, but it’s not an outlier. The city shares its surface water supply with a network of communities across the region, and they all draw from the same mineral-rich watershed. That shared source is why you’ll see similar hardness complaints from one suburb to the next.

The practical effect of that regional geology is that hardness in this part of Texas tends to run high across the board. Cities that pull from the same reservoirs and lakes are dealing with the same dissolved calcium and magnesium, and their readings land in a similar range. Some nearby municipalities show slightly lower numbers, often because of differences in treatment blending or because they supplement with additional sources. But nobody in this corner of the state is bragging about soft water straight from the tap.

What does that mean for you as a Richardson resident? It means the scale building up in your water heater and the film on your shower doors are not unique to your neighborhood. They’re the standard cost of doing business with North Texas surface water. According to the Water Quality Association, hard water raises energy, appliance-wear, and cleaning costs across the board, and that estimate scales with your actual hardness. At 11.8 GPG, you’re on the higher end of that curve.

The WQA’s industry estimate, based on 2010 data and roughly $1,230 in 2026 dollars when CPI-adjusted, is a starting point, not a fixed bill. Your actual number depends on household size, water usage, and appliance efficiency. But the direction is clear: harder water costs more money, and Richardson’s water is firmly in the very hard category.

Battelle Memorial Institute research backs that up on the appliance side. Their 2009 study found roughly 4% gas water-heater efficiency loss for every 5 GPG of hardness in a typical 50-gallon-per-day household. At 11.8 GPG, you’re looking at a meaningful efficiency hit just from mineral buildup. The Department of Energy puts an even finer point on it: a quarter-inch of scale can cut water-heater efficiency by up to 40%. And hard water shortens water-heater service life by roughly 30-50% compared to soft water.

The good news is that hardness is treatable, and the fix is well understood. But first, it helps to know exactly what you’re up against. At 11.8 GPG, you’re not dealing with a marginal issue; you’re dealing with water that will leave its mark on your pipes, your appliances, and your cleaning routine until something changes.

How does Richardson stack up against the rest of Texas? It's very hard at 11.8 GPG — Midland, The Woodlands, and College Station sit nearby with different numbers. See the full hardest-water ranking for context.

See where Richardson sits on the Texas water hardness map →

Want the broader explainer on what hardness actually is and how it behaves? Read hard water vs. soft water, explained.