Ultraviolet (UV) Water Disinfection Systems

Yes. UV is the standard fix for bacteria in well water. UV-C light at 254 nm delivers 99.99% (4-log) inactivation of E. coli, total coliform, Giardia, Cryptosporidium, and viruses with no chemicals and no taste change. Two conditions: the system has to deliver the right dose at your flow rate (NSF 55 Class A, 40 mJ/cm2, for a confirmed positive test), and the water reaching the chamber has to be pre-treated clear, with iron under 0.3 ppm, hardness under 7 gpg, turbidity under 1 NTU, and a 5-micron sediment prefilter ahead of the lamp. UV is disinfection, not filtration: it removes nothing except live microorganisms.

Our residential Viqua systems run $895 to $2,495. The VH200 (9 GPM at 30 mJ/cm2, 1-3 baths, NSF 55 Class B supplemental) is $895; the flagship NSF 55 Class A VH410 (14 GPM at the certified 40 mJ/cm2 dose, 3-5 baths) is $995; the Water Sanitizer combo (sediment + carbon + UV) is $1,195; and the sensor-monitored F4 Plus (36 GPM at 30 mJ/cm2) is $2,495. Light-commercial Class A PRO20 and PRO30 systems run $4,395 and $5,895. Budget roughly $160 per year for the annual replacement lamp.

A UV disinfection system is the whole-house answer for Giardia. Giardia and Cryptosporidium cysts are chlorine-resistant, which is why chlorination alone is a weak defense against them, but both are highly susceptible to UV: a Class A system delivers 99.99% inactivation at every tap. Fine mechanical filtration rated 1 micron absolute can also physically remove cysts at a single point of use. For whole-home protection on a well, the standard setup is a 5-micron sediment prefilter followed by a UV chamber installed last in the treatment train.

Yes, when three conditions are met. First, the dose class matches the job: NSF/ANSI 55 Class A (40 mJ/cm2) for confirmed contamination, Class B only as supplemental protection on water already deemed acceptable. Second, the water is pre-treated clear so the light actually reaches the microbes (UV transmittance above 75%). Third, the lamp is replaced every 12 months, because output decays with age even though the light still looks blue. Two honest limits: UV leaves no residual in the pipes downstream, and it only disinfects while powered, so the lamp runs 24/7.

Yes. Whole-house UV systems are built exactly for private wells. A point-of-entry chamber on the main line disinfects every tap in the house. We carry the VIQUA line: the VH200 for smaller homes (9 GPM at 30 mJ/cm2, Class B supplemental), the Class A VH410 for confirmed coliform or E. coli in 3-5 bath homes, the sensor-monitored F4 Plus for high-flow homes, and the Class A PRO20/PRO30 for estates and light-commercial buildings. UV always installs last, after iron, softening, and sediment pre-treatment, and the right class depends on your lab result, which is why we ask for the test before we size anything.

NSF/ANSI 55 Class A UV is validated at a 40 mJ/cm2 dose and is the system for KNOWN contamination: if a lab has confirmed coliform or E. coli in your water, you want Class A. The Viqua VH410, PRO20, and PRO30 are Class A.

Class B UV is certified at a lower 16 mJ/cm2 dose and is meant for supplemental disinfection of water that is already considered safe, as an extra layer of protection. The Viqua VH200 is Class B. It is a fine belt-and-suspenders choice for a smaller home, but if your test came back positive for bacteria, step up to the Class A VH410.

No. UV is disinfection, not filtration. It inactivates living microorganisms and removes nothing else: no iron, no manganese, no hardness, no sulfur smell, no chlorine, no sediment. The water that comes out is microbiologically safe but otherwise chemically identical to the water that went in.

Those other problems have to be handled upstream with the right equipment: an iron filter for iron and manganese, a softener for hardness, a carbon filter for chlorine and chemicals, and a sediment filter for grit. Tell Aidan what your water test shows and he will lay out the full sequence with UV in its correct spot at the end.

Yes. A 5-micron sediment prefilter is mandatory ahead of the UV chamber. UV needs clear water: any sediment, turbidity, iron, or color in the water either blocks the light or builds up on the quartz sleeve and shadows the lamp, which lets microbes pass through untreated. The worst part is that this failure is silent, the light still glows, but the dose is no longer reaching the bugs.

Pre-treatment thresholds to hit before UV: iron under 0.3 ppm, manganese under 0.05 ppm, hardness under about 7 gpg, turbidity under 1 NTU, and UV transmittance above 75%. If your water is over any of these, install the matching filter upstream first.

Usually no. Municipal water is already disinfected and carries a chlorine or chloramine residual all the way to your tap, so a whole-house UV chamber is generally unnecessary on city water.

The honest exceptions are specific: a private well, a spring, a cistern, a boil-water-prone system, or a household with immunocompromised members who want an extra barrier. If you are on city water and considering UV, call us first. We would rather talk you out of equipment you do not need than sell it to you.

Use copper for the short pipe runs immediately at the UV chamber. Stray UV light degrades PEX and other polymer tubing over time, so copper is the durable choice right at the lamp. Customers who have installed our systems call this out specifically.

PEX is fine everywhere else in the house. Your plumber simply transitions from PEX to two short copper stubs at the chamber inlet and outlet with standard fittings, then back to PEX downstream.

When the power is out, the UV lamp is off and the water passing through is not being disinfected. After any extended outage, run the cold taps for a minute to flush the chamber once power returns, and the lamp resumes full disinfection right away.

If your well also relies on an electric pump, you usually have no water pressure during an outage anyway, so there is nothing flowing through the chamber. For households that need continuous protection through outages, a battery backup or generator on the UV circuit is the answer.

Replace the UV lamp about once a year on the VH200 and VH410 (the lamp is rated for roughly 9,000 hours, or about 12 months of continuous use). The PRO20 and PRO30 use amalgam lamps that can last up to 2 years. The controller counts down and alarms before the lamp is due, so you are never running on a spent bulb.

A genuine Viqua replacement lamp runs about $145 to $165 depending on the model, so the ongoing cost is roughly a lamp a year plus an occasional quartz sleeve. We stock the lamps, sleeves, and controllers for every system we sell.

Yes, and that is exactly the right use case. Shock chlorination is a one-time disinfection of the well itself. If the source keeps getting recontaminated (a shallow or spring-fed well, surface influence, a compromised well cap, or septic proximity), the bacteria returns within weeks and you are back to re-shocking.

A permanent Class A UV system disinfects every gallon as it is used, so you stop chasing the problem. If your well is also fouling from iron bacteria or heavy organics, UV alone is not enough: those wells need pre-treatment or continuous chlorination, and we will tell you honestly which path fits your situation.