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UV Disinfection Calculator

Dose selection (UVDGM) · UVT correction · electrical power & lamp-count estimate · validation rules

iWhat this tool does

UV dose is a physical quantity — irradiance × time — validated by bioassay. This tool turns your permit into a design dose, corrects for water quality (UVT), and estimates the power and lamp count for budgeting. Final lamp counts come from a vendor's validated dose-delivery curves — this sheet makes every vendor bid against the same basis.

1Flow & discharge target

Dose presets below follow the UVDGM / NWRI validated RED basis: 30 mJ/cm² = municipal coliform floor (TCEQ §217.295) · 40 = 4-log bacteria · 80 = reuse-class (Title-22 grade). Click a preset or type your own.

Design avg flow Q m³/d

Peak factor^[3] (1.5–2.5)×

Design dose^[2] (30–80)mJ/cm²

UVT₂₅₄^[3][4] (55–80)%

Effluent TSS to UV^[2] (≤ 30)mg/L

Lamp type^[4]

UVT → lamp-factor table (reference)

UVT₂₅₄	Relative lamps (65 % = 1.00)
75 %	0.75
70 %	0.87
65 %	1.00
60 %	1.15
55 %	1.35

Literature: every 5 points below 60 % adds ~15–20 % lamps. Interpolated linearly here.

Results — dose & reactor estimate

Peak flow to UV

—m³/h

Electrical power

—kW

Lamp count (est.)

—lamps

Item	Value	Unit

Dose table — reference (UVDGM RED)

Organism	2-log	3-log	4-log
E. coli / bacteria	15	25	40
Giardia lamblia	5.0	11	20
Cryptosporidium	5.8	12	22
Hepatitis A	21	30	45
Adenovirus	85	140	186

RED = reduction-equivalent dose from validated biodosimetry [1]. Note adenovirus: if virus credit matters (reuse), the dose is set by adenovirus, not bacteria.

UV instrumentationMAPPED TO OUR RANGE

Duty	Instrument	Model / spec	Qty

Quote the UV train's instruments at factory price

Flow-paced dose control needs reliable flow and effluent-quality signals — we supply those at the manufacturer's ex-works price with no mark-up (our margin is the export tax rebate).

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Sources & parameter basis

[1]	US EPA, UV Disinfection Guidance Manual (UVDGM) / NWRI guidelines — RED tables by organism & log credit.
[2]	TCEQ §217.295 — 30 mJ/cm² floor for activated-sludge effluent; UVT ≥ 65 %; TSS/BOD ≤ 30 mg/L; bioassay validation (scale ≤10×, ≥4 lamps).
[3]	UV retrofit engineering guidance (2026) — UVT bands 60–75 % secondary, peak factor 2.0–2.5, single-module-out redundancy 75 %, dose escalation for reuse 40–80.
[4]	UV supplier engineering data — LP 254 nm / MP polychromatic characteristics, lamp life, sleeve fouling, intensity sensors, energy band 0.02–0.05 kWh/m³ @30 mJ/cm².

This is a budgeting estimate, not a procurement design. Regulatory UV design requires a bioassay-validated reactor matched to your UVT and peak flow. Use the numbers above to set the design basis and compare vendors — then procure against their validated dose-delivery curves.

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