Well water treatment in the Hill Country means building the right set of stages for what your particular well brings up: sand in the kitchen faucet aerator after a big rain, water hard enough to scale a water heater in five years, an orange tint in the tub, a whiff of sulfur off the hot tap. Sometimes it is a lab result: if a well test came back positive for coliform, that is common after storms and very fixable.
Absolute Water Solutions has been building well-house systems out of Spicewood since 2003, and the approach has not changed: test what is actually in the water, then build the treatment train the test calls for. Nothing more.
What a Hill Country well is actually pulling up
Water quality on a private well is up to the owner: the groundwater districts manage how much gets pumped, not what comes out of your tap, and TCEQ's guidance is a simple annual bacteria and nitrate test.
Most wells from Dripping Springs to Spicewood to Liberty Hill are finished in the Trinity aquifer; on the Llano Uplift side (Round Mountain, northern Blanco County, Marble Falls), deeper wells hit the Ellenburger-San Saba dolomite. These are deep holes, 600 feet and more on the Leander fringe, and very little of any given rain ever reaches water that deep, which is why a wet spring does not refill a well.
What that water carries is fairly predictable:
- Hardness, almost always. A USGS survey of 480 Blanco County wells found 467 "very hard"; Trinity water is the same story.
- Sediment and sand after rain, or when a pump is chasing a falling water table.
- Iron, manganese and hydrogen sulfide. Iron exceeded 0.3 mg/L in 45% of the Blanco County wells sampled for it; sulfate ran over 250 mg/L in 18%.
- Coliform bacteria, especially in karst wells after a flood, and nitrate near livestock (over 45 mg/L in 20% of the Blanco County samples).
- Radium and gross alpha in some Trinity wells. Liberty Hill's own Hensell wells tested 3.8 pCi/L combined radium in 2022, 76% of the federal limit.
- Rising TDS and salinity as drought pulls levels down; the Middle Trinity runs over 1,000 mg/L TDS across much of the Onion and Barton Creek watersheds.
The well-house treatment train
Every recommendation starts with a water test: hardness, TDS, pH, iron and sediment in the house, bacteria, nitrate and radium at the lab. If you are buying a place on a well, do this before closing.
Worth knowing
Well water filtration is built in stages, in a fixed order, and every stage protects the one after it:
- Pressure tank first. Everything downstream is sized to your pump's flow and the pressure tank's draw-down, not to the number of bathrooms.
- Spin-down filter. A clear-bowl screen that catches sand and grit and flushes with a valve turn: the first thing to install when the water is cloudy or sandy.
- Cartridge sediment filter. Five-micron polishing so the media beds and UV lamp downstream see clear water.
- Softener or conditioner for the hardness that is the baseline on every Trinity and Ellenburger well.
- Iron or sulfur filter if the test shows it (the air-injection or oxidizing stage), covered in the iron and sulfur removal section below.
- UV for disinfection.
- Reverse osmosis at the kitchen for TDS, sulfate, fluoride, radium and taste.
That is the ceiling, not the standard package; plenty of wells need stages two, four and six and nothing else. The order matters more than the count: a backwashing filter needs more flow than the house does, and a UV lamp cannot disinfect water it cannot see through.
Softening well water, and why iron matters
A well water softener is sized in grains per gallon against the tested hardness and the pump's flow, not off a chart. Two things are different on a well. First, iron: dissolved iron fouls softener resin, so if the test shows more than a trace, an iron stage goes ahead of the softener. Second, septic: nearly every well home is also on an OSSF, and Texas Health and Safety Code 366.013 only allows softener discharge to a septic system from a demand-initiated regeneration (DIR) unit, which is what we install. The rotten eggs article walks through telling a heater smell from a well smell, and softener sizing and repair live on the water softeners page.
Iron and Sulfur Removal
An iron filter for well water is how we clear up the staining Hill Country wells are known for: orange or rust stains in the toilet and tub that come back a week after you scrub them, rust streaks under the spout, and laundry comes out yellow no matter what goes in the wash. Iron and manganese are aesthetic problems, not health ones; the EPA's secondary standards (0.3 mg/L for iron, 0.05 mg/L for manganese) mark where staining begins, not where water becomes unsafe. Iron shows up three ways. Clear-water (ferrous) iron is dissolved: the water runs clear, then turns orange in a glass left on the counter, and it is the form an air-injection filter is built for. Red-water (ferric) iron arrives already oxidized and turns the sediment prefilter orange in weeks. Manganese stains black or dark brown, oxidizes more slowly, and needs the right pH and a catalytic media; a filter sized for iron alone will pass it. Iron bacteria are the fourth case: reddish-brown slime in the toilet tank and a swampy smell that gets mistaken for sulfur. They call for shock-chlorinating the well and, if they return, a chlorination system ahead of the filter rather than an air-injection unit that feeds them oxygen.
An air-injection iron filter is a single tank with a control valve and a pocket of air held at the top. Incoming water sprays through the air, oxygen converts dissolved iron into solid particles, a catalytic media bed traps them, and on a schedule the valve backwashes the bed to drain and draws a fresh charge of air. No chemical feed, no salt, no cartridges. Two numbers decide whether it is the right tool: the iron, manganese and hydrogen sulfide level from the test, and the well's flow rate, because a backwash needs several gallons a minute to lift the bed and most Blanco County wells yield only 10 to 25 gpm. On a low-yield well we match the tank to the pump or backwash from a storage tank.
Sulfur is tested on site, because hydrogen sulfide leaves a sample bottle as fast as it leaves the tap. If the water smells like rotten eggs, especially hot water, and the cold tap is fine, the source is usually the water heater's magnesium anode rod, which is heater work rather than a filter. When every tap smells, the gas is coming up the well: low levels drop out in the same air-injection tank, moderate levels get a dedicated sulfur filter for well water loaded with catalytic carbon, and heavy loads, or sulfur combined with high iron, manganese or iron bacteria, get chlorination, a retention tank, a backwashing filter and a carbon polish so the house never tastes the chlorine. Whatever the stage, it sits ahead of the softener: resin fouls once iron passes roughly 0.3 mg/L, and no cleaner brings it back. The equipment we use for this is on the air-charged iron filter and ozone generator pages.
Bacteria: UV and chlorination
If a well test came back positive, the sequence is straightforward: boil or use bottled water, shock-chlorinate the well and the plumbing, retest, then decide on permanent disinfection. We install Viqua UV systems behind a five-micron sediment filter and, where hardness would coat the quartz sleeve, behind the softener; for persistent contamination or heavy iron, a chlorination feed with a contact tank is the other route. The depth on disinfection lives on the water purification page. We schedule the earliest business-day visit we have and get you through the boil-water period with a plan.
Lake and Surface Water Treatment
A lake water filtration system is what turns raw surface water into water you can drink and shower in, for lake houses that pump straight out of Lake Travis or Lake LBJ and for Hill Country homes that collect rainwater. Raw lake water has never been filtered by anything: turbidity that sits around 1 to 3 NTU and climbed past 400 NTU in the October 2018 Llano River flood, roughly 4 mg/L of dissolved organic carbon, Giardia and Cryptosporidium cysts, about 10 grains per gallon of limestone hardness, and since 2017 zebra mussel larvae, which plug a raw water intake and, when a mass of them dies off inside the line, give the water the pond odor Austin Water customers reported in 2019. A lake water treatment system for home use is therefore a chain in a fixed order: a screened intake set below the low-water line (Lake Travis swung about 45 feet between February 2024 and September 2026), a backwashing sediment filter, fine filtration to 1 micron absolute for the cysts, carbon sized for the organic load behind the algae taste in the water each summer, UV where the water is clear enough for the lamp or chlorination with a retention tank where it is not, and RO at the kitchen tap. Many lake homes add a softener after filtration; the test decides. Everything goes in an insulated enclosure, because the dock pump and shoreline line are the parts most exposed to a freeze. Any owner pumping from the Highland Lakes also needs an LCRA domestic-use contract ($165 per acre-foot, 0.75 acre-foot minimum, about $124 a year), and a house with a second supply needs backflow protection so raw water never crosses into the treated side.
Rainwater collection filtration is the other surface water we build. Off the roof it is soft and slightly acidic, so it skips the softener and gets a neutralizing stage for copper plumbing, a first-flush diverter ahead of the tank, then sediment, carbon, UV (standard on a cistern, not optional, because the first rain after a dry spell flushes turbidity and bacteria into the tank at once) and usually RO at the tap. Seasons matter on both supplies: spring spawning loads the intake screen, summer blooms are when the water is cloudy and tastes of algae, fall floods and lake turnover bring bottom water up, and drought concentrates everything. From Spicewood we cover the south shore including Briarcliff and Highland Lake Estates, the water filtration systems Lago Vista, TX lakefront owners run on the north shore, and Lake LBJ at Horseshoe Bay, where the whole town runs on lake water. A water test whenever the water changes on you is the standard check.
Low-yield wells, drought and floods
Typical Blanco County yields are 10 to 25 gpm; Ellenburger wells range from 3 to 45, and March 2026 monitoring showed the worst Hays Trinity aquifer levels in twenty years. A pump chasing a falling water table pulls sand and air, and a low-yield well cannot backwash a media filter; the fix is a storage cistern with a float switch and a booster pump that gives the treatment train the flow it needs. After a flood like July 2025, karst wells are most likely to go cloudy or test positive, so retest.
Well country we serve
We work wells across the Dripping Springs acreage subdivisions, the Ellenburger and Trinity wells around Johnson City, Round Mountain and Marble Falls, our home ground in Spicewood, Briarcliff and Highland Lake Estates, the lake homes of Lago Vista and Horseshoe Bay, and the well-and-septic lots west of Liberty Hill.
Whether it is sand in the aerator, hard water, or a lab report you would like a second pair of eyes on, call (512) 587-8188 during business hours, Monday through Friday, or request a free estimate.