Arsenic in well water is not a problem most Fresno County homeowners think about until they test their water and find it. Then it becomes the only problem that matters.
This is not a hypothetical scenario. The San Joaquin Valley — including Fresno County and surrounding areas — has one of the highest concentrations of arsenic-affected private wells in the United States. The U.S. Geological Survey has documented elevated arsenic across a broad swath of California's Central Valley, with groundwater in many areas exceeding the EPA's maximum contaminant level (MCL) of 10 micrograms per liter (10 ppb or parts per billion).
California's own MCL for arsenic, set under the Safe Drinking Water Act, is 10 ppb — consistent with the federal standard. But the science on arsenic is clear: there is no established safe level. Long-term exposure to even levels below the MCL has been associated with increased risk of bladder, lung, and skin cancers, as well as cardiovascular disease and developmental problems in children.
If your Fresno-area home is on a private well, you are responsible for testing it. The county does not test your well for you. And if arsenic is present, the municipal water treatment that protects city water users does nothing for you.
This guide examines which water treatment companies — national brands and local providers — actually remove arsenic effectively from well water, what the technology looks like, what it costs, and why not all "water filtration" claims are equal when it comes to this specific, serious contaminant.
The Arsenic Problem in Fresno County: Scope and Sources
Arsenic enters groundwater through two primary pathways: natural geological sources and agricultural activity.
Natural geological sources dominate in Fresno County. The Sierra Nevada foothills and the sedimentary deposits of the San Joaquin Valley contain arsenic-bearing minerals. As water percolates through these formations over thousands of years, it dissolves arsenic compounds and carries them into the aquifers that private wells tap.
Agricultural activity compounds the problem. Historical use of arsenic-based pesticides — lead arsenate was widely used on cotton and other crops in the Central Valley through the mid-20th century — has left residual arsenic in soils that can leach into shallow groundwater.
The result: private wells in rural and semi-rural Fresno County show arsenic at concentrations ranging from barely detectable to well over 50 ppb in some locations. A 2019 study published in the journal Environmental Science and Technology found that more than 2 million Californians — disproportionately in the San Joaquin Valley — were exposed to arsenic above the federal MCL in their drinking water.
Small community water systems and private wells are the primary exposure pathway. City of Fresno municipal water is tested and treated; private wells in unincorporated Fresno County are not.
If you're on a private well in Fresno County, the only way to know your arsenic level is to test. And if it's elevated, the only solution is a properly designed treatment system.
[Schedule a free water test for your Fresno-area well](/free-water-test?utm_source=blog&utm_medium=seo&utm_campaign=comparison_blogs&utm_content=42-arsenic-well-water-fresno)
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How Arsenic Is Removed From Water: The Technology That Works
Not all water treatment removes arsenic. This is the critical thing to understand when evaluating any company's claims. Many popular systems — standard carbon filters, basic water softeners, most pitcher filters — do not remove arsenic or remove it only marginally.
Here are the technologies with documented efficacy for arsenic removal:
Reverse Osmosis (RO)
Reverse osmosis forces water through a semi-permeable membrane at pressure. The membrane's pore size is small enough to reject arsenic ions. A properly designed RO system with a functioning membrane typically removes 90–98% of arsenic from drinking water.
RO is the most commonly recommended point-of-use treatment for arsenic in private wells. It's well-understood, widely available, and cost-effective for drinking and cooking water. The limitation: it treats water at a single point (typically under the kitchen sink), not the whole house. You would still be exposed to arsenic through showering and bathing — though dermal absorption of arsenic from bathing water is generally considered a much lower risk than ingestion.
For whole-house RO — treating all water entering the home — the system becomes significantly larger and more expensive due to the volume of water involved.
Activated Alumina Filtration
Activated alumina (aluminum oxide) media has a strong affinity for arsenic, particularly arsenate (As V), the form predominant in most oxygenated groundwater. When water passes through an activated alumina bed, arsenic adsorbs onto the media surface. The media is eventually exhausted and must be replaced or regenerated.
Activated alumina filters can be installed as whole-house point-of-entry systems, treating all water entering the home. They are particularly effective when pH is optimized (slightly acidic pH enhances performance). Removal rates of 95–99% are achievable in properly designed systems.
Iron Oxide/Greensand Filtration
When well water contains both arsenic and iron (a common combination in Fresno County), iron-removal media can simultaneously remove both contaminants. Arsenic tends to bind to iron hydroxide particles, so systems that oxidize and filter iron can co-remove arsenic. However, performance for arsenic alone is less consistent than dedicated activated alumina systems.
Anion Exchange
Specialized anion exchange resins can remove arsenate effectively. These systems are sometimes used in combination with other treatment for comprehensive removal, particularly when multiple anions (nitrate, fluoride, arsenic) need to be addressed simultaneously.
What Does NOT Work for Arsenic
- Standard whole-house carbon/sediment filters: minimal to no arsenic removal
- Water softeners: do not remove arsenic
- UV systems: do not remove arsenic
- Standard under-sink carbon filters: minimal arsenic removal
- Pitcher filters (Brita, etc.): generally not effective for arsenic
This distinction matters enormously when evaluating what water treatment companies are actually offering you.
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Culligan: Arsenic Treatment Is Available, But Verify What You're Getting
Culligan offers arsenic treatment options, including under-sink RO systems and some whole-house media systems. Their Good Water Machine RO is a capable point-of-use system that achieves meaningful arsenic reduction.
The concern with Culligan for Fresno well water customers is the dealer model. Your Fresno-area Culligan dealer may or may not have strong expertise in arsenic-specific system design. The quality of the water analysis and the appropriateness of the recommended system depend heavily on the individual dealer's knowledge and honesty.
Culligan's RO systems carry NSF/ANSI 58 certification for arsenic reduction when properly maintained. Membrane replacement — typically every 2–3 years — is essential for maintaining performance. Culligan service contracts include this, which can be convenient.
Verdict for arsenic removal: Culligan can do this, but verify NSF certification for arsenic specifically on whatever system is recommended, and get the actual arsenic reduction percentage in writing. Do not accept vague assurances.
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RainSoft: Premium System, Verify Arsenic-Specific Certifications
RainSoft's whole-house systems focus primarily on iron oxidation, softening, and general filtration. Their drinking water systems include RO options. For arsenic, you'd typically be directed to their drinking water RO unit.
The challenge with RainSoft for arsenic: their sales presentations emphasize aesthetic water quality (taste, odor, hardness) and the in-home demo is designed to be dramatic. Arsenic is invisible, tasteless, and odorless — it doesn't make for impressive demo moments. There's a risk that arsenic concerns get secondary treatment in a RainSoft sales process.
If you pursue RainSoft for a Fresno well water system with arsenic concerns, specifically ask about NSF/ANSI 58 certification for arsenic reduction and request documentation of the system's tested removal percentage.
Verdict for arsenic removal: Possible through their RO drinking water systems, but arsenic expertise is not their primary focus.
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Puronics: California Experience Helps, But Verify
Puronics' California roots mean their dealers have more exposure to the Central Valley arsenic problem than national brands centered elsewhere. Their iFlow and whole-house filtration systems can be configured with arsenic treatment components.
Puronics dealers in the Fresno area should be familiar with the arsenic issue. Whether any given dealer has the expertise to properly design an arsenic-specific system is something you should verify directly, asking for their experience with well water arsenic treatment specifically.
Verdict for arsenic removal: Better California-specific knowledge base than some national brands. Verify dealer expertise and system certifications.
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Kinetico: Comprehensive Well Water Systems Available
Kinetico has a clear well water product line including their Sulfur Guard, MacroGuard, and drinking water systems that can be configured for arsenic reduction. Their dealer model means local expertise varies, but Kinetico as a brand has genuinely invested in multi-contaminant well water treatment.
Their K5 Drinking Water Station with appropriate cartridge selection achieves NSF/ANSI 58 certification including arsenic reduction. The cartridge-based approach allows the system to be customized for specific well water chemistry.
The limitation remains price and dealer availability. A comprehensive Kinetico system for a Fresno well addressing arsenic, hardness, and potentially other contaminants can reach $4,000–$8,000 installed.
Verdict for arsenic removal: Genuine capability with appropriate system configuration. Price is the primary constraint.
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EcoWater: Standard RO Available, Arsenic Is One Option Among Many
EcoWater's drinking water RO systems can address arsenic. Their ERO 385 and similar systems carry NSF certifications including arsenic reduction. If you're purchasing through Costco or a similar retail channel, the system itself is solid.
The challenge: EcoWater's retail channel does not provide arsenic-specific consultation. You need to know to ask for it. If your Fresno well has elevated arsenic, the standard EcoWater pitch may not specifically address it unless you push.
Verdict for arsenic removal: The technology works. The consultation and guidance may not.
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SpringWell: Whole-House Arsenic Filtration Available Direct
SpringWell offers a dedicated arsenic removal whole-house system — their arsenic removal filter uses activated alumina and is rated for whole-house point-of-entry treatment. This is a legitimate, properly designed arsenic removal system available at competitive direct pricing ($600–$1,200 depending on configuration before installation).
For Fresno well owners who want whole-house arsenic treatment (addressing bathing, laundry, and all household water, not just drinking water), SpringWell's system is one of the few at this price point that specifically targets arsenic.
The limitation: no local presence for consultation, installation, or service. You'd need a plumber willing to work with the system, and any troubleshooting happens via online support. For a contaminant as serious as arsenic, many homeowners want local professional oversight.
Verdict for arsenic removal: Solid dedicated arsenic filtration at competitive price. Best for well-informed DIY-capable customers.
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APEC: Strong RO Performance for Arsenic at Point of Use
APEC's reverse osmosis systems are among the best-reviewed in the under-sink RO category. Their ROES-50 and premium series systems achieve documented arsenic reduction rates of 93–97% in independent testing.
For a Fresno well owner who wants excellent point-of-use protection for drinking and cooking water, APEC delivers excellent results at $200–$400. This does not address whole-house exposure, but for primary ingestion concern, it's effective and affordable.
APEC systems are NSF/ANSI 58 certified on key components and widely available online.
Verdict for arsenic removal: Excellent point-of-use RO choice. Does not address whole-house arsenic.
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Aquasana: Their RO Systems Address Arsenic
Aquasana's OptimH2O under-sink RO system is specifically marketed with arsenic reduction and carries NSF/ANSI 58 certification. Aquasana has invested in making their arsenic reduction claims verifiable, which is commendable.
Their system retails for around $300–$400 and provides effective point-of-use arsenic reduction for drinking water.
Like APEC, this does not provide whole-house arsenic treatment.
Verdict for arsenic removal: Good certified point-of-use RO option. Know that it's only treating drinking water, not bathing water.
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Pelican: Whole-House Plus RO Combination
Pelican offers whole-house filtration and drinking water RO combinations that can address arsenic at both levels. Their premium combo systems ($2,000–$4,000 installed) include an under-sink RO with arsenic reduction certification.
Pelican's whole-house carbon filtration does not specifically target arsenic — for that, the RO component is the key treatment step. So the "whole-house" claim is somewhat misleading for arsenic specifically; only the drinking water RO achieves high-efficiency arsenic reduction.
Verdict for arsenic removal: The RO component addresses drinking water arsenic well. Whole-house arsenic removal would require additional targeted media.
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LifeSource: Does Not Address Arsenic
LifeSource's whole-house filtration system is a carbon-based filter designed primarily for chlorine and sediment reduction. It does not address arsenic. For a Fresno well owner with arsenic concerns, LifeSource is not the answer.
Verdict for arsenic removal: Not effective for arsenic. Wrong tool for this problem.
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Generation H2O: Limited Local Presence for Fresno Wells
Generation H2O's systems can potentially be configured with RO or arsenic-specific media. Their presence in the Fresno area for private well consultation and service is limited. For a contaminant as serious as arsenic, having local expert support for design, installation, and monitoring is important.
Verdict for arsenic removal: Limited local Fresno capability for well-specific arsenic systems.
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Home Valley Solutions: Arsenic Expertise Built for Central Valley Well Water
Home Valley Solutions was built in the Central Valley. The team understands that Fresno County well water arsenic is not an edge case — it's a documented, widespread problem that affects real families in this community every day. This shapes how they approach every private well consultation.
Comprehensive Testing That Includes Arsenic
A standard water softener salesperson in Fresno might test your hardness and TDS and call it a day. Home Valley Solutions' free well water testing goes further, because the team knows that Central Valley well water often carries multiple concerns simultaneously: arsenic, nitrates, hardness, iron, elevated TDS, and potentially bacteria.
You cannot design the right treatment system without knowing what you're treating. This is why the free water test matters so much — and why it needs to be genuinely comprehensive, not a demo designed to sell a specific product.
[Get your free well water test in Fresno County](/free-water-test?utm_source=blog&utm_medium=seo&utm_campaign=comparison_blogs&utm_content=42-arsenic-well-water-fresno)
Reverse Osmosis Systems That Certified Remove Arsenic
For drinking water protection, Home Valley Solutions installs reverse osmosis systems with documented, certified arsenic reduction. They do not recommend systems that "may help" with arsenic — they recommend systems that are tested and certified to specific reduction percentages. The difference is critical when your health is the stake.
[Learn about reverse osmosis systems for well water](/services/reverse-osmosis?utm_source=blog&utm_medium=seo&utm_campaign=comparison_blogs&utm_content=42-arsenic-well-water-fresno)
Whole-House Arsenic Treatment for Complete Protection
If your well water arsenic level is significantly elevated, point-of-use drinking water treatment alone may not be sufficient, especially for households with children, pregnant women, or other at-risk individuals who may have significant arsenic exposure through bathing. Home Valley Solutions can design and install whole-house arsenic treatment systems using activated alumina or other appropriate media, matched to your specific water chemistry.
[Explore whole-house water filtration options](/services/water-filtration?utm_source=blog&utm_medium=seo&utm_campaign=comparison_blogs&utm_content=42-arsenic-well-water-fresno)
Multi-Contaminant System Design
Fresno County well water rarely has just one problem. Arsenic commonly co-occurs with:
- High hardness (10–25 gpg common)
- Elevated iron and manganese
- Nitrates from agricultural activity
- High TDS
- Sediment from older wells
A properly designed well water treatment system addresses all of these in the right sequence. Home Valley Solutions designs systems with the correct treatment train — sediment prefiltration, iron removal, arsenic treatment, softening where needed, and RO or alkaline drinking water at the tap.
[Explore alkaline water options](/services/alkaline-water?utm_source=blog&utm_medium=seo&utm_campaign=comparison_blogs&utm_content=42-arsenic-well-water-fresno)
Bilingual Consultation for Fresno's Communities
Fresno County has one of California's largest Spanish-speaking populations, including many families in rural and semi-rural areas served by private wells where arsenic is most prevalent. Home Valley Solutions conducts all consultations and service in English or Spanish — ensuring that language is never a barrier to understanding what's in your water and what to do about it.
Post-Installation Monitoring and Service
Arsenic removal systems require maintenance to stay effective. RO membranes need periodic replacement (typically every 2–3 years). Activated alumina media is eventually exhausted and needs regeneration or replacement. Home Valley Solutions provides local follow-up service and can schedule maintenance reminders so your system continues performing at rated efficiency.
Phone: (559) 507-6838
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Arsenic Removal Comparison: What the Numbers Actually Mean
| Technology | Arsenic Reduction | Point of Use or Whole House | Maintenance Required |
|---|---|---|---|
| Reverse Osmosis (RO) | 90–98% | Point of use (under sink) | Membrane every 2–3 years |
| Activated Alumina (whole house) | 95–99% | Whole house (point of entry) | Media replacement/regeneration |
| Standard carbon filter | 0–10% | Either | Filter replacement |
| Water softener | 0% | Whole house | Salt, resin maintenance |
| UV system | 0% | Either | Bulb replacement |
| Salt-free conditioner | 0% | Whole house | Minimal |
The lesson: if a company is recommending a standard carbon filter or water softener for your arsenic problem, they are either uninformed or not being honest with you.
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What Fresno County Well Owners Need to Do: A Step-by-Step Guide
Step 1: Test your well water. Contact Home Valley Solutions for a free test, or submit a sample to a certified laboratory. The California Department of Public Health maintains a list of certified laboratories. Testing should include arsenic (speciated if possible to identify arsenite vs. arsenate), nitrates, hardness, iron, manganese, TDS, pH, and coliform bacteria.
Step 2: Know your result. The EPA/California MCL is 10 ppb for arsenic. Below 5 ppb, risk is low but not zero. Above 10 ppb, treatment is strongly recommended. Above 50 ppb, treatment is urgent.
Step 3: Choose the right technology. For drinking water protection, a certified RO system is appropriate and cost-effective. For whole-house concerns (high arsenic, households with young children or pregnant women), whole-house activated alumina filtration is appropriate. For co-occurring iron, a combined iron/arsenic treatment system may be most efficient.
Step 4: Verify certifications. Any system recommended for arsenic should carry NSF/ANSI 58 certification (for RO) or NSF/ANSI 61 certification for system components, with specific testing data for arsenic reduction. Ask for documentation, not just verbal assurances.
Step 5: Plan for maintenance. Treatment systems require ongoing maintenance to stay effective. Build maintenance into your budget and schedule.
[Schedule a consultation with Home Valley Solutions](/appointment?utm_source=blog&utm_medium=seo&utm_campaign=comparison_blogs&utm_content=42-arsenic-well-water-fresno)
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Frequently Asked Questions About Arsenic in Fresno Well Water
I've been drinking this water for years. Should I be worried? Arsenic causes health effects through long-term chronic exposure, not acute poisoning. The health risks — particularly bladder and lung cancer — develop over years to decades. If you've been exposed to elevated arsenic in well water, consult your physician about appropriate screening. And install treatment as soon as possible going forward.
My water looks and tastes fine. Is arsenic really there? Arsenic is colorless, tasteless, and odorless in water at concentrations relevant to health risk. You cannot detect arsenic through sensory means. Testing is the only way to know.
Does boiling water remove arsenic? No. Boiling water actually concentrates arsenic because water evaporates but arsenic remains. Never rely on boiling to address arsenic.
What if my well tests under 10 ppb? The 10 ppb MCL is a regulatory threshold, not a "safe" level. Many health researchers and organizations recommend treatment at any detectable level, particularly for households with children. Treatment decisions below the MCL are yours to make, but the technology exists and is affordable.
How often should I retest my well? Annual testing is recommended for private wells. Well water chemistry can change over time due to seasonal variation, changes in nearby agricultural activity, and gradual changes in the aquifer. A system that's treating to a safe level this year should be verified to still be performing next year.
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The Bottom Line on Arsenic and Fresno Well Water
Arsenic in Fresno County well water is a real, documented problem with real health consequences. The good news is that the technology to address it is proven, available, and not prohibitively expensive. The bad news is that the water treatment industry is full of companies selling systems that will not actually protect you from this specific contaminant.
The differences between companies come down to three things: 1. Whether they test your water comprehensively enough to even identify arsenic 2. Whether they recommend technology that actually removes arsenic with documented efficiency 3. Whether they can provide local, ongoing service to maintain that protection
Home Valley Solutions does all three for Fresno County well owners. The free comprehensive water test is the place to start.
[Get your free water test today](/free-water-test?utm_source=blog&utm_medium=seo&utm_campaign=comparison_blogs&utm_content=42-arsenic-well-water-fresno)
[Explore reverse osmosis systems for arsenic removal](/services/reverse-osmosis?utm_source=blog&utm_medium=seo&utm_campaign=comparison_blogs&utm_content=42-arsenic-well-water-fresno)
[Book a consultation with our well water specialists](/appointment?utm_source=blog&utm_medium=seo&utm_campaign=comparison_blogs&utm_content=42-arsenic-well-water-fresno)
Call us directly at (559) 507-6838 — bilingual English/Spanish service available.
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Home Valley Solutions serves Fresno, Clovis, Sanger, Reedley, Selma, Fowler, Kerman, and throughout Fresno County. Licensed water treatment specialists with expertise in Central Valley well water contamination. Bilingual English/Spanish consultations available.
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