HOROWHENUA · OFFICIAL COUNCIL DATA
What's actually in Horowhenua's tap water
Horowhenua District Council answered all three parts of the request inside its 20 working days, with a full year for the five supplies it runs - Levin, Foxton, Foxton Beach, Shannon and Tokomaru: 1,040 onsite chlorine readings, 330 network E. coli samples, six quarterly by-product rounds and two metals rounds per supply, plus the Levin plant's hourly fluoride record. What it shows: no E. coli in any network sample, fluoride in Levin only, lead no higher than 0.0016 mg/L, and chlorination by-products in every supply - Foxton's trihalomethanes reached 82% of the New Zealand limit. The free check reads your address.
THE HEADLINE NUMBERS
Five supplies, by-products in every one.
Every network reading in the release sits inside New Zealand's legal limits. Horowhenua District Council treats its water properly, and its own results show it - the raw river and stream tests show what the plants take out. The same results show what stays in the water at the tap: trihalomethanes in all six quarterly rounds of every supply, 932 times the EWG health guideline at Foxton's peak, and fluoride in Levin. Lead was quantified only in Foxton and Tokomaru, at a sixth of the legal limit or less. The numbers are below; what you do about them is up to you.
SUPPLY BY SUPPLY
What was found in your supply
Chlorine, pH and turbidity roughly weekly at three to seven sites per supply; E. coli and coliforms in the lab through the year; by-products each quarter and metals twice a year. These are the council's own results. Typical figures are medians; peaks are the highest single sample.
| Supply | Chlorine, typical | THMs, highest sample | Haloacetic acids | Worth knowing |
|---|---|---|---|---|
| Levin | 0.82 mg/L | 0.0212 mg/L | Not detected | fluoridated, 0.81 mg/L typical; 58 E. coli samples, none detected; lead below detection in both metals rounds |
| Foxton | 1.12 mg/L | 0.1399 mg/L | 0.08 mg/L | not fluoridated; 82% of the combined THM limit on 2 March 2026; 77 E. coli samples, none detected; lead 0.0016 mg/L, inside the 0.01 limit |
| Foxton Beach | 0.09 mg/L | 0.1092 mg/L | 0.06 mg/L | not fluoridated; free chlorine ran low, below 0.1 mg/L in most Surf Club and Boat Club readings; 91 E. coli samples, none detected |
| Shannon | 0.81 mg/L | 0.0372 mg/L | Not detected | not fluoridated; 53 E. coli samples, none detected; lead below detection in both rounds |
| Tokomaru | 1.26 mg/L | 0.0866 mg/L | 0.081 mg/L | not fluoridated; chlorine peaked at 2.09 mg/L, the district's highest; 51 E. coli samples, none detected; lead 0.0006 mg/L |
Source: Horowhenua District Council LGOIMA release, reference 1429, answered 11 September 2026. Chlorine typicals are medians of the operators' onsite free-chlorine readings at three to seven reticulation sites per supply, roughly weekly, 14 August 2025 to 13 August 2026 - 1,040 readings after removing 67 duplicate entries and one Tokomaru reading keyed as 10.17 mg/L (re-read 0.93 the same afternoon) - with pH and turbidity from the same visits. E. coli and coliform figures are the council's Eurofins reticulation samples plus its weekend Central Environmental Laboratories certificates, 330 samples, none with either. THM figures are the highest per-sample totals from six quarterly rounds, 1 September 2025 to 4 June 2026, summing the quantified species; the ratio against New Zealand's combined limit is recomputed from the species, because the lab's printed ratios for the September 2025 round do not follow from its own species values and are not used. Haloacetic acids are per-sample sums of the acids that quantified, each held against its own limit in the report: dichloroacetic acid peaked at 0.032 mg/L in Tokomaru and 0.02 in Foxton against its 0.05 limit, trichloroacetic acid at 0.06 in all three against its 0.2 limit, and every acid was below detection in every Levin and Shannon sample. Metals: two six-monthly rounds per supply at one reticulation tap each; lead quantified only at the Foxton and Tokomaru fire stations. Fluoride figures are the Levin plant's online analyser on the water leaving the plant, not a reticulation tap; one negative analyser reading is excluded. Raw bore, river and stream results are carried as notes only. The regulator's own national extract holds a 7.545 mg/L chlorine value for Levin, Shannon and Foxton on 12 February 2025 and 100 mg/L for Tokomaru on 28 February 2025; both pre-date this release, which neither confirms nor refutes them. No PFAS or microplastics tests anywhere in the release.
WHAT THIS MEANS FOR YOUR HOUSE
Three things to know.
By-products above the guideline, in every supply
Chlorine meeting natural organic matter forms trihalomethanes and haloacetic acids, and three of the five supplies here are river or stream fed. Foxton's THM peak of 0.1399 mg/L on 2 March 2026 is 932 times the EWG health guideline and 82% of the way to New Zealand's combined limit; Foxton Beach reached 0.1092 and Tokomaru 0.0866, while Levin and Shannon stayed under 0.04. Haloacetic acids quantified in Foxton, Foxton Beach and Tokomaru - dichloroacetic acid up to 0.032 mg/L against its 0.05 limit - and never reached detection in Levin or Shannon.
Why treatment matters: the Ohau River
The council also tests its raw water, and the Ohau River feeding Levin returned E. coli in 24 of 26 fortnightly samples, from 5 to past the lab's 80 counting ceiling. The Mangaore Stream at Shannon ran the same way, E. coli in 20 of 24, and the Tokomaru River in 19 of 24. Foxton and Foxton Beach draw on bores, and those came back almost clean - one or two detections in a year of samples. That is untreated source water going into clarification, filtration, chlorine and UV, and it is not your tap water: 330 network samples, none with E. coli. Closing the gap is the plant's job; what it leaves behind is the point of this page.
Fluoride in Levin, low chlorine at Foxton Beach, and almost no lead
The Levin plant fluoridates, and its own analyser recorded 0.81 mg/L typically across 9,537 hourly readings, peaking at 1.24 against a 1.5 legal limit; the other four supplies add none. Foxton Beach's free chlorine ran at 0.09 mg/L typical, below 0.1 in most readings at the Surf Club and Boat Club, on bore water carrying 1.75 to 3.27 mg/L of ammonia - the field sheet measures free chlorine only, so this page cannot say what combined chlorine was doing. Lead was quantified only at the Foxton and Tokomaru fire stations, 0.0016 and 0.0006 mg/L, inside the 0.01 limit. Not one PFAS or microplastics test was run.
YOUR ADDRESS
This is the district picture. Get the report for your home.
The free water check takes about two minutes, and it includes the PDF water report for your address - written from the same release, read for your house.
THE SYSTEM THAT FITS
What we'd fit in Horowhenua.
Fluoride, THMs and the PFAS and microplastics nobody tests for only come out at the kitchen tap with reverse osmosis, and that's the ES60's job. If it's the chlorine in your showers that bothers you, that's a whole-house filter - we supply those by arrangement, so call us on 021 709 370.
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