Drinking Water Disinfection

No single disinfection technology is optimal for every pathogen and every plant condition. Chlorine is highly effective against bacteria but weak against Cryptosporidium. UV inactivates Cryptosporidium and Giardia but leaves no residual. Chloramines provide long-lasting residual in the distribution network but slower primary disinfection. Best-in-class utilities combine technologies to cover every pathogen class while controlling DBPs.

A modern multi-barrier program typically includes:

• Primary disinfection — UV, ozone, or free chlorine at the plant to achieve required log-inactivation of bacteria, viruses, and protozoa.
• Secondary disinfection — Chloramines or low-level free chlorine to maintain a measurable residual throughout the distribution system.
• DBP control — pH adjustment, ammonia dosing for chloramine formation, and source-water management to keep trihalomethanes (THMs) and haloacetic acids (HAAs) below regulatory limits.

• CT compliance (Concentration × Time)
  Surface Water Treatment Rule requires a minimum CT to achieve log-inactivation of Giardia, viruses, and Cryptosporidium. Variable or inaccurate dosing puts CT compliance at risk every minute.
• DBP regulatory limits
  EPA Stage 2 D/DBP Rule caps total THMs at 80 µg/L and HAA5 at 60 µg/L as locational running annual averages. Overdosing chlorine generates excess DBPs and triggers violations.
• Distribution residual
  Most utilities target 0.2–1.0 mg/L free chlorine or 1.0–4.0 mg/L total chloramine at the customer tap. Maintaining this across thousands of km of pipe requires booster-station dosing with the same precision as plant dosing.
• Cryptosporidium and Long-Term 2 ESWTR
  Bin classification drives required additional inactivation; UV is often the primary technology, but chemical residual must still be maintained downstream.

Modern utilities are moving beyond pump-on-a-shelf installations toward pre-engineered, skid-mounted dosing packages that integrate pumps, pulsation dampeners, calibration columns, back-pressure valves, safety relief, and instrumentation into a single delivered unit. This dramatically shortens commissioning, simplifies maintenance, and provides documented performance from day one.

• Deep municipal expertise
  Pumps and systems installed at thousands of utilities worldwide, from small communities to mega-cities.
• Full chemistry coverage
  PVDF, PTFE, ceramic, and 316L wetted parts handle every common disinfectant, oxidant, and carrier solution.
• Engineered systems
  Our ETO systems remove the engineering risk from plant builds and upgrades.
• Regulatory authority
  Milton Roy maintains a dedicated Water Treatment Regulatory Compliance Guide covering SDWA, NPDES, EU Drinking Water Directive, and emerging PFAS rules.
• Cross-portfolio strength
  Pairs naturally with Ingersoll Rand sister brands LMI (compact chemical feed pumps), Seepex (sludge handling), and ARO (AODD pumps).