San Patricio County, TX

These figures come from wells tested in San Patricio County, TX, not from any one well.

Sulfate is not common in wells in San Patricio County, TX (3 of 57 tested wells were over). Only a test tells you about your own well.
Wells in San Patricio County, TX are typically very hard (58 wells tested).
Too few wells have been tested in San Patricio County, TX (3) to say how common iron is.

What to test for

Start with the four this site covers:

Most well owners also test for these. We point to the source and don't interpret the results.

arsenic: occurs naturally in groundwater in many regions. USGS: arsenic and drinking water
nitrate: common near farmland and septic systems. EPA: private drinking water wells
total coliform bacteria: the standard yearly well check. EPA: private drinking water wells
lead and copper: from household plumbing, especially when pH is below 6.5. EPA: lead in drinking water
PFAS: several states run private-well sampling programs. EPA: PFAS
a certified lab: states certify labs and some run their own private-well programs. Texas's certified-lab list (from your state drinking-water program)

County figures describe the wells sampled there, not any one well. Exact counts, sample years and sources are below.

Level it's compared with	0.3 mg/L
Share of wells over the level	0.0%
Wells over the level / wells judged	0 of 3
Median	0.01 mg/L
Years sampled	1955–1965
Wells	3
Test results	3
Wells left out	0
Sources	USGS (3)

Fewer than 10 wells behind this figure; treat it as a hint, not a prior.

Level it's compared with	none; hardness is shown in bands
Share of wells very hard	55%
Median	190 mg/L as CaCO₃
Years sampled	1938–1965
Wells	58
Test results	61
Wells left out	0
Sources	USGS (58)

Level it's compared with	250 mg/L
Share of wells over the level	5.3%
Wells over the level / wells judged	3 of 57
Median	45 mg/L
Years sampled	1938–1965
Wells	57
Test results	60
Wells left out	0
Sources	USGS (57)