Edwards Aquifer

Aquifer · Texas

Serves 9 cities in our database · ~4,904,162 residents

260
Avg Hardness (PPM)
16.9
Avg PFAS (ppt)
2.3
Avg Lead (ppb)
9
Cities Served
Soft
0Slightly
60Moderate
120Hard
180Very Hard
250Extreme
400+
260 PPM Extremely Hard
CONTAMINANT LEVELS Hardness 260 PPM TDS 410 PPM PFAS 16.9 ppt Lead 2.3 ppb Chlorine 1.3 mg/L Nitrate 1 mg/L

About Edwards Aquifer

The Edwards Aquifer is the primary water source for San Antonio and the Texas Hill Country. It is one of the most prolific artesian aquifers in the world, but population growth is straining supply.

Geography & Hydrology

The aquifer stretches 180 miles along the Balcones Fault Zone in south-central Texas. The recharge zone — where rainfall enters the aquifer — runs through the rapidly developing Hill Country. Spring-fed rivers like the Comal and San Marcos depend on aquifer levels.

How Edwards Aquifer Water Is Treated

Edwards Aquifer water is naturally very hard (200-300 PPM) due to limestone dissolution. Treatment includes chlorine disinfection and fluoride. San Antonio Water System has diversified sources to reduce dependence on the aquifer.

Across the 9 cities we track, water from Edwards Aquifer averages 260 PPM hardness (Extremely Hard), ranging from 240 to 285 PPM. This is very hard water - most homeowners benefit from a water softener.

PFAS concern: Cities supplied by Edwards Aquifer average 16.9 ppt PFAS, exceeding the 2024 EPA limit of 4 ppt. An NSF P473 certified filter is recommended for drinking water.

Current Challenges

Rapid population growth in the recharge zone, drought vulnerability (single-source dependence), endangered species dependent on spring flows (legal pumping limits), and increasing hardness as water levels fluctuate.

Cities Supplied by Edwards Aquifer

Water quality varies by city due to local treatment, distribution infrastructure, and source blending.

San Antonio, TX

240 PPM · Very Hard 2,113,151 residents

San Antonio West, TX

260 PPM · Extremely Hard 2,113,151 residents

Georgetown, TX

260 PPM · Extremely Hard 191,639 residents

Round Rock North, TX

255 PPM · Extremely Hard 130,662 residents

New Braunfels, TX

285 PPM · Extremely Hard 116,477 residents

Cedar Park North, TX

260 PPM · Extremely Hard 86,939 residents

San Marcos, TX

250 PPM · Extremely Hard 72,970 residents

Schertz, TX

280 PPM · Extremely Hard 41,948 residents

Copperas Cove, TX

250 PPM · Extremely Hard 37,225 residents

Recommended for Edwards Aquifer Water

Based on average water quality across 9 cities supplied by Edwards Aquifer.

Water Softener SpringWell SS1 ~$1,495 Scale Remover CLR Calcium Lime Rust ~$10 PFAS Filter Clearly Filtered Pitcher ~$90

Affiliate disclosure: we may earn a commission on purchases. Recommendations based on water quality data.

Frequently Asked Questions

Is Edwards Aquifer water safe to drink?
Water from Edwards Aquifer meets EPA safety standards in all served cities. However, average PFAS levels of 16.9 ppt exceed the 2024 EPA health guideline. A certified water filter is recommended for drinking water.
Why is Edwards Aquifer water so hard?
Edwards Aquifer water picks up dissolved calcium and magnesium from the limestone and mineral formations it passes through underground. At 260 PPM average, this makes it extremely hard.
How many people drink Edwards Aquifer water?
Edwards Aquifer supplies drinking water to 9 cities in our database, serving approximately 4,904,162 residents. The largest cities include San Antonio, TX; San Antonio West, TX; Georgetown, TX.
Do I need a water filter for Edwards Aquifer water?
Yes. With PFAS averaging 16.9 ppt, a reverse osmosis or activated carbon filter is recommended. Look for NSF P473 certification.