Water Line Chlorination and BAC-T Testing FAQ

My water sample failed. What do I do now?

A failed bacteriological sample usually means either the line was not disinfected properly, the sample was pulled too early, or the sampling point was contaminated. It does not always mean the pipe is bad. The fix is to re-chlorinate the affected section, flush it correctly, and re-sample under clean conditions.

Call us and we will get out there, figure out where the failure came from, and re-run the disinfection and testing. Every job we have completed has cleared bacteriological testing on the first pass, so we know what causes failures and how to keep them from repeating.

Why won't the inspector sign off on my water line?

The most common reason is that the domestic water system hasn't been disinfected or tested and cleared through bacteriological testing, or the paperwork doesn't satisfy the authority having jurisdiction. Most AHJs won't release a system for use until they have a passing bacteria test from an ELAP accredited laboratory, along with documentation of the disinfection, or for short runs under 18 linear feet, documentation of the sampling alone. That exemption mostly isn't observed at hospitals and other HCAI-regulated facilities, which generally require full chlorination regardless of footage.

We handle both the disinfection and the lab reporting, and we deliver a documentation package formatted for the AHJ reviewing your job. We have cleared inspection with SFPUC, EBMUD, HCAI (formerly OSHPD), San Jose Water Company, Cal Water, and more than twenty other jurisdictions across Northern California.

Do I need chlorination for a small remodel?

It depends on how much new pipe went in. As a general rule, new domestic water piping over 18 linear feet requires full chlorination and disinfection. Under 18 feet, most jurisdictions will accept bacteriological sampling alone without a full chlorination, though this exemption is mostly not observed at hospitals and other HCAI-regulated facilities, which generally require full chlorination regardless of footage.

That threshold catches a lot of people off guard on tenant improvement and remodel work, because the job feels small but still triggers the requirement. If you are not sure which side of the line your job falls on, send us the scope and we will tell you.

How long does water line chlorination take?

There are two accepted methods and the timeline depends on which one your specification calls for. The 24 hour method holds a chlorine concentration of 25 mg/L in the line for a full day. The 3 hour method uses a much higher concentration, 200 mg/L, for a shorter contact period. Both are recognized under AWWA C651.

After the contact period ends, the line gets flushed until chlorine residual returns to normal system levels, then samples are pulled and sent to the lab. Lab turnaround for bacteriological results is typically 24 hours. If your schedule is tight, the 3 hour method can save you most of a day, and we can tell you whether your specification allows it.

What is AWWA C651 and does my job need it?

AWWA C651 is the American Water Works Association standard for disinfecting water mains and potable water piping. It is the document most specifications and inspectors point to when they require disinfection.

If your job includes new domestic water piping, a new water main, or a main that was opened for repair, it almost certainly falls under C651 or your local equivalent. Building interior domestic water systems are typically governed by California Plumbing Code Section 609.10, which follows the same disinfection principles.

Who handles bacteriological testing and lab reporting?

We do, end to end. BAC-T is short for bacteriological testing, which checks new or repaired potable water piping for Total Coliform and E. coli before the system can be released for use.

We collect the samples, maintain chain of custody, and run them through Eurofins Built Environment Testing West, an ELAP accredited laboratory (ELAP #3094). You get a certified lab report you can hand directly to the inspector.

Do you provide closeout documentation?

Yes. Every job closes out with a turnover package you can hand directly to the inspector, owner, or GC. It includes the written disinfection procedure, certificates of analysis and SDS for the NSF 60 certified sodium hypochlorite, meter calibration certificates, signed field logs with chlorine residual readings, the certified lab report from Eurofins Built Environment Testing West (ELAP #3094), and operator credentials, including SWRCB Grade D1 License #50366.

Healthcare, public works, and owner QA teams often ask for more than a passing lab result. Our package is built to cover that, so closeout doesn't stall waiting on paperwork.

Can you disinfect a new water main?

Yes. We disinfect new and repaired water mains using the continuous feed method and the spray down method, both covered under AWWA C651. This includes ductile iron, PVC, and other main line materials, along with reservoirs, tanks, and clearwells.

Water main work is priced on the internal volume of the pipe rather than linear footage, since that is what actually determines chemical demand. We also provide dechlorination when residual levels exceed what the local sewer authority will accept for discharge.

Do you clean and flush heating and chilled water systems?

Yes. We perform chemical cleaning and flushing for closed loop hydronic systems, including heating hot water (HHW), chilled water (CHW), and low conductivity water (LCW) loops. This covers pre cleaning of new systems, removal of mill scale, oil, and construction debris, and chemical treatment at startup.

We also handle cooling tower passivation and chemical startup. For systems that require a corrosion inhibitor, we charge the loop to the specified concentration. Low conductivity water loops are cleaned and flushed only, with no inhibitor added, because inhibitor chemistry raises conductivity beyond what those systems tolerate.

Do you sanitize DI and RO water systems?

Yes. We sanitize high purity water systems, including deionized (DI) and reverse osmosis (RO) loops, USP Purified Water systems, laboratory water systems, dialysis water treatment, and pharmaceutical and biotech process piping.

We use Minncare cold sterilant, a peracetic acid based sanitizer, at the manufacturer recommended one percent concentration and full recommended contact time. This matters, because underdosing at a lower concentration or cutting contact time short is common and does not achieve validated sanitization.

Do you work on hospital and healthcare projects?

Yes, and a large share of our work is healthcare. We have completed disinfection and clearance testing on projects at Kaiser, Stanford, UCSF, Laguna Honda, O'Connor Hospital, Rideout Regional Medical Center, and others.

Healthcare projects reviewed by HCAI (formerly OSHPD) require a complete documentation package, not just a passing lab result. We provide the full reporting set needed for hospital sign off and project closeout.

Do you work on federal and public works projects?

Yes. We are registered with the California Department of Industrial Relations (DIR #1000911400) and perform work in compliance with prevailing wage and public works requirements.

We have completed projects at Lawrence Livermore National Laboratory, Beale Air Force Base, the VA Palo Alto Health Care System, and municipal projects for the Cities of Martinez, Vacaville, Antioch, Napa, Capitola, and Fairfield.

What does disinfection and BAC-T testing cost for a hospital or office build-out?

Domestic water disinfection is priced as a flat number based on the fixture count, not the length of pipe, so routing changes during construction don't change your price. The main things that move the number are the fixture count on the domestic water system, the number of sampling points and whether HPC testing is required, and the travel distance to the site. Water mains are priced on the internal volume of the pipe instead.

Send us the plans or a fixture count and the job location, and we will get you a firm number within 24 hours.

How fast can you get a quote back to me?

Within 24 hours of getting your scope. Send plans, a fixture count, or just a description of what went in and we will turn around a firm number. We are a single operator outfit, so there is no chain of approvals slowing down your buyout.

How quickly can you get out to a job site?

Usually within a few days, and faster when a job is holding up closeout or an inspection date. Because the same licensed operator performs every job, scheduling does not depend on crew availability. Call us with your date and we will tell you straight away whether we can hit it.

What licenses do you hold?

State Water Resources Control Board Grade D1 Water Distribution Operator, License #50366. Qualified Applicator License (QAL), required in California because chlorination is regulated as microbial pest control. Department of Industrial Relations registration #1000911400 for public works. Laboratory partner: Eurofins Built Environment Testing West, ELAP #3094.

Every job is performed and overseen personally by a licensed D1 operator.