E. COLI
Not detectedAt the reporting limits, across the tested samples.
OFFGRID WATER / TESTING & RESEARCH
Know what’s in your water.
Lab tests show what our systems can do with real river water. The full setup is designed to take really dirty water and treat it for everyday use at home or on board, with a final RO stage for drinking water.
We even tested the RO unit with raw water straight from the River Trent to see what it would produce. We weren’t disappointed. You can see the results below.
RIVER LEA / MARCH 2024
A customer challenged us. We put it to the test.
He wasn’t convinced Stage One could handle River Lea water. So we took it to the river in March 2024, at a difficult time of year for water quality, filtered a sample and sent it to an independent lab.
E. coli was below the lab’s reporting limit in the filtered sample. You can see that result below, alongside our RO and rainwater tests.
INDEPENDENT LAB TESTING
What the lab found
The findings below come from our March 2024 laboratory report. The full results are available to inspect.
RIVER TRENT / RO
2.89mg/L nitrateNitrate in the tested reverse-osmosis sample.
RAINWATER / UF
0cfu/100 mLTotal coliforms in the tested rainwater sample.
How the readings compare
The shaded columns show higher readings from published studies of untreated water. These are separate samples from different places and dates, not matched before-and-after tests.
Canal & river water
| Measurement | Untreated canal¹Published upper reading | River LeaAfter Stage One | River TrentThrough RO |
|---|---|---|---|
| Total coliformscfu/100 mL | >2,420MPN/100 mL | 3 | 0 |
| E. colicfu/100 mL | >2,420MPN/100 mL | <1 | 0 |
| Nitratemg NO3/L | 100 | 16.5 | 2.89 |
Collected rainwater
| Measurement | Untreated rainwater²Published upper reading | RainwaterThrough UF |
|---|---|---|
| Total coliformscfu/100 mL | 100 | 0 |
| Nitratemg NO3/L | 12.06 | <0.05 |
0 None detected in the portion tested. < Below the laboratory’s reporting limit.
Bacterial counts: filtered samples and the rainwater reference use cfu/100 mL. The canal reference uses MPN/100 mL, a different counting method.
View the full laboratory results
All measurements, as reported by Mercian Science / Simplex Health. Samples collected 15 March 2024; report issued 22 March 2024.
| Measurement | River LeaAfter Stage One | Filtered + TRO“Chlorified”³ | River TrentThrough RO | RainwaterThrough UF |
|---|---|---|---|---|
| Total coliformscfu/100 mL | 3 | 0 | 0 | 0 |
| E. colicfu/100 mL | <1 | 0 | 0 | 0 |
| Intestinal enterococcicfu/100 mL | 0 | 0 | 0 | 0 |
| Phosphatemg PO4/L | 0.365 | <0.050 | <0.050 | <0.050 |
| Ammoniamg NH3/L | 0.01 | <0.01 | 0.22 | 0.37 |
| Nitratemg NO3/L | 16.5 | <0.05 | 2.89 | <0.05 |
River Lea · Stage One
| Total coliformscfu/100 mL | 3 |
|---|---|
| E. colicfu/100 mL | <1 |
| Intestinal enterococcicfu/100 mL | 0 |
| Phosphatemg PO4/L | 0.365 |
| Ammoniamg NH3/L | 0.01 |
| Nitratemg NO3/L | 16.5 |
Filtered + TRO “Chlorified”³
| Total coliformscfu/100 mL | 0 |
|---|---|
| E. colicfu/100 mL | 0 |
| Intestinal enterococcicfu/100 mL | 0 |
| Phosphatemg PO4/L | <0.050 |
| Ammoniamg NH3/L | <0.01 |
| Nitratemg NO3/L | <0.05 |
River Trent · RO
| Total coliformscfu/100 mL | 0 |
|---|---|
| E. colicfu/100 mL | 0 |
| Intestinal enterococcicfu/100 mL | 0 |
| Phosphatemg PO4/L | <0.050 |
| Ammoniamg NH3/L | 0.22 |
| Nitratemg NO3/L | 2.89 |
Rainwater · UF
| Total coliformscfu/100 mL | 0 |
|---|---|
| E. colicfu/100 mL | 0 |
| Intestinal enterococcicfu/100 mL | 0 |
| Phosphatemg PO4/L | <0.050 |
| Ammoniamg NH3/L | 0.37 |
| Nitratemg NO3/L | <0.05 |
Sources & laboratory details
1. Canal reference
Grand Union Canal, Grove Lock. Maximum readings in the 2021–22 dataset: total coliforms >2,420, E. coli >2,420 MPN/100 mL and nitrate 100 mg/L. These are individual parameter maxima, not one sample or a typical average.
Read the canal report, table 3-72. Rainwater reference
UCL roof-fed water butt, London, 2010–12. The higher reported readings were 100 cfu/100 mL for total coliforms and 12.06 mg/L for nitrate. These are study upper readings, not UK averages. Roof condition and storage affect water quality.
Read the UCL study, pages 82–843. Laboratory report
Mercian Science / Simplex Health, SH59754 / 24-03412. The River Lea sample had passed through Stage One. “Filtered + TRO Chlorified” is the original sample label; its exact treatment sequence is unverified. The untreated references are separate published samples and cannot be used to calculate removal percentages. Results apply to the samples tested.
Laboratory notes: tests reported outside UKAS accreditation; a sample-temperature deviation was recorded.
THE OFFGRID WATER QUALITY PROJECT
Help us map water quality.
We’re starting a project to understand what’s in the water people actually use, across canals, rivers, rainwater systems, wells and boreholes.
The aim is a growing map of water quality: what’s being found, where, and how it changes. Your test results can help us spot patterns, choose new testing locations and better understand what different sources need.
More environments
Different waterways, collection systems and storage conditions.
Broader lab testing
Our next round will aim to cover a wider range of contaminants.
Matched samples
We plan to collect untreated and filtered samples from the same source.
Project starting now. Customer test submissions are open.
CHOOSING THE RIGHT TREATMENT
Different filters do different jobs.
The right combination depends on your source water, intended use and maintenance. Ask us if you’re unsure which setup you need.
Sediment & carbon
Sediment filters catch dirt and particles. Carbon helps with chlorine, taste, odour and certain chemicals.
Ultrafiltration & UV
UF traps many microorganisms. UV inactivates them in suitably clear water. Neither removes dissolved salts.
Reverse osmosis
RO reduces dissolved salts and certain chemicals that particle filters leave behind. It adds a dedicated drinking-water stage.
The paperwork behind the page
Original laboratory report
The source for every filtered-water result on this page: SH59754 / 24-03412, March 2024.
Request the lab reportRO & UV-C documents
Ask for the component certificates and supplier documents for your model.
Request model documentsWhat does NSF/ANSI 58 cover?
NSF/ANSI 58 covers reverse-osmosis systems and components. Check the named model and the claims listed on its certificate. A component certificate does not cover the whole installation.
Check the standard with NSFUpdated 9 October 2026.