14 to 1the vote carrying the PFAS motion, resolution C-26/1161, 29 September 2026

7 to 8the vote that lost an amendment leaving out the two Mardi Dam clauses

16 of 16treated-water samples, July to September 2026, below 0.001 micrograms per litre for each guideline compound

5 of 13Ourimbah Creek catchment sites sampled on 5 August 2026 that Council’s notes put above a guideline value

Is the tap water affected?

If you drink town water on the Coast, Council’s own published answer is no. Its PFAS page says The Central Coast drinking water supply remains safe and compliant with the Australian Drinking Water Guidelines for PFAS. Its quarterly summary for July to September 2026 puts numbers on it: 16 samples of treated drinking water, and for each of the four PFAS compounds that carry a guideline value, PFOS, PFHxS, PFOA and PFBS, the average and the maximum for the quarter were both below 0.001 micrograms per litre, the detection limit Council’s monitoring reports give.

Treated drinking water, July to September 2026

  • PFOS, guideline value 0.008max <0.001
  • PFHxS, guideline value 0.03max <0.001
  • PFOA, guideline value 0.2max <0.001
  • PFBS, guideline value 1max <0.001

Micrograms per litre, 16 samples in the quarter. The guideline values are those Council lists for the Australian Drinking Water Guidelines, which it says were updated in July 2025.

From Council’s quarterly summary of drinking water quality, July to September 2026, and its PFAS and drinking water page, read 9 October 2026.

That is not the same as never. Council’s treated-water results list 11 results with a detection, on five sampling dates, none higher than 0.003 micrograms per litre and each noted as below the guidelines. The most recent is 0.001 of PFOS at Ettalong on 14 May 2026.

What Council decided

The notice of motion from Cr Kyle MacGregor, seconded by Cr Jane Smith, came up at 7.43pm on 29 September, at the adjourned sitting of the 22 September meeting. We set out its nine parts when it was listed. Most of it asks NSW agencies to act: to investigate PFAS in fish, yabbies and other aquatic life in Ourimbah Creek, to issue advice and put up signs if levels warrant it, and to advise whether residents who pump untreated creek water should hold off during and after floods. Two parts ask Council to act itself, at Mardi Dam. Part 4 reads:

Arranges an appropriately designed PFAS sediment investigation within Mardi Dam or alternatively obtain independent expert advice on the scope of sampling required to determine whether PFAS has accumulated within dam sediments and whether any concentrations identified require further ecological, operational or public-health assessment.

Part 4 of resolution C-26/1161, Ordinary Council Meeting minutes, 22 September 2026, page 40

Part 5 adds that any such investigation should include, where practicable, sediment cores or other sampling capable of distinguishing recent deposition from historical accumulation.

Cr Doug Eaton OAM, seconded by Cr Jared Wright, moved an amendment. We compared it with the motion part by part: it is the same text with parts 4 and 5 taken out, and nothing added. It kept the request for a report on the outcome of any Mardi Dam sediment investigation, but not the parts that would have Council arrange one. It was lost 7 to 8, and the motion then carried 14 to 1.

Amendment · moved by Cr Eaton

The motion without parts 4 and 5: no Council-arranged Mardi Dam sediment investigation or expert advice on its scope

For7

  • Mayor McNamara
  • Cr Mouland
  • Cr Daniels
  • Cr McKinna
  • Cr Eaton OAM
  • Deputy Mayor Stanton
  • Cr Wright

Against8

  • Cr MacGregor
  • Cr Castles
  • Cr Crowley
  • Cr Walsh
  • Cr Neal
  • Cr Smith
  • Cr Lamont
  • Cr McWaide

Lost

Motion C-26/1161 · moved by Cr MacGregor

All nine parts, including the Mardi Dam sediment investigation or expert advice (part 4) and the sediment cores (part 5)

For14

  • Mayor McNamara
  • Cr Mouland
  • Cr Daniels
  • Cr MacGregor
  • Cr Castles
  • Cr Crowley
  • Cr Walsh
  • Cr Neal
  • Cr McKinna
  • Cr Smith
  • Cr Lamont
  • Deputy Mayor Stanton
  • Cr Wright
  • Cr McWaide

Against1

  • Cr Eaton OAM

Carried

How the two votes on item 8.2 fell, as recorded in the Ordinary Council Meeting minutes of 22 September 2026, pages 39 to 42. The one-line summaries are ours; the names, counts and results are the minutes’.

What the officers had advised

Councillors went further than the officers’ advice, which was in the agenda. The Chief Executive Officer’s response said Council’s position is that these matters should first be led and technically advised by the relevant NSW Government agencies before Council commits to any additional Council-funded investigations. On Mardi Dam specifically, it said any future sediment investigation should be guided by the findings and recommendations of the independent PFAS Management Plan a specialist consultant is preparing for Council’s water and sewer operations, and related specialist advice. The cost was left open:

The financial exposure cannot be determined until the scope of any investigations is confirmed and advice is received from the relevant NSW Government agencies.

Financial Impact, item 8.2, Ordinary Council Meeting agenda, 22 September 2026, page 87

The resolution does leave Council a cheaper first step. Part 4’s alternative, independent expert advice on the scope of sampling, is close to what officers themselves suggested asking the State for: advice on The need for, and scope of, any sediment investigations within Mardi Dam.

What Council’s own tests found in the creek

Most of the motion is about people who do not drink town water: those who fish Ourimbah Creek and those who pump straight from it. For them the relevant numbers are in Council’s catchment monitoring, which it publishes. On 5 August 2026 Council sampled 13 sites in the Ourimbah Creek catchment. Four had no PFAS detected. Four, on Ourimbah Creek itself (sites 5, 16 and 17) and at site 6, had detections of 0.001 to 0.002 micrograms per litre, noted as below the guidelines. Five had results Council’s own notes put above a guideline value: four that its site list places on Stringybark Creek, which joins Ourimbah Creek, or upstream of it, and one it describes as a pond.

The five sites above a guideline value, 5 August 2026, micrograms per litre
SitePFOSPFHxSPFOAPFBS
Guideline value0.0080.030.21
7, Stringybark Ck north arm0.0080.0340.0190.043
9, upstream of Stringybark Ck0.0070.1220.0430.123
10, a pond0.0380.140.1120.158
11, Stringybark Ck0.0080.1020.0450.122
12, Stringybark Ck south arm0.0340.2560.1020.248

Source: Council’s Ourimbah Creek catchment PFAS monitoring results, August 2024 to August 2026, pages 2 and 16 to 17. Bold marks the values Council’s notes call above the guidelines; none of the five is above for PFOA or PFBS. Site descriptions are shortened from Council’s site list, without the property names it uses as landmarks. The same day, sites 2, 3, 8 and 13 had nothing detected, and sites 5, 6, 16 and 17 had detections below the guidelines.

Two cautions. Council’s own page says The Australian Drinking Water Guidelines apply to treated drinking water only. Creek water is not drinking water, so Council’s notes use the guidelines as a yardstick, and these are not breaches of anything. But that yardstick is exactly the one that matters to a household that drinks creek water untreated, which is the group parts 6 to 8 of the resolution are about.

The pattern also fits what the officers told councillors, that concentrations fall away downstream. The highest result, 0.256 micrograms per litre of PFHxS at site 12, is about eight and a half times the PFHxS guideline value, on our arithmetic. At the Ourimbah Creek sites and site 6 the same day, no result was higher than 0.002.

The sentence about the pump station

One sentence in the officers’ response does not match Council’s own published results, and it is the sentence about the point where Council takes water from the creek.

Current investigations indicate that PFAS detections within the catchment are associated with an Environment Protection Authority licensed site, with concentrations reducing significantly downstream and remaining below detection limits at Council's water extraction point (PS11).

Chief Executive Officer Response, item 8.2, Ordinary Council Meeting agenda, 22 September 2026, page 86

Council’s site list describes site 6 as Water Pump Station 11 north / west of Ourimbah interchange of M1. Its results for site 6 cover 28 sampling dates from 8 August 2024 to 5 August 2026. Nothing was detected on 4 of them. On the other 24, at least one compound was detected, at 0.001 to 0.006 micrograms per litre, each noted as below the guidelines. The latest, on 5 August 2026, was 0.002 of PFOS, 0.002 of PFHxS and 0.001 of PFBS.

Site 6, Water Pump Station 11: every sampling date, August 2024 to August 2026

One dot per date, in order. Every detection was below the guideline values.

8 Aug 2024 to 10 Jul 2025

  1. 8 Aug 2024: not detected
  2. 13 Nov 2024: PFHxS 0.002, PFBS 0.001
  3. 2 Dec 2024: PFOS 0.002, PFHxS 0.003, PFBS 0.001
  4. 12 Dec 2024: PFOS 0.002, PFHxS 0.002, PFOA 0.002, PFBS 0.001
  5. 15 Jan 2025: PFHxS 0.002
  6. 23 Jan 2025: PFOS 0.001, PFHxS 0.003, PFOA 0.001, PFBS 0.002
  7. 6 Feb 2025: PFHxS 0.002, PFBS 0.001
  8. 13 Feb 2025: PFHxS 0.002
  9. 18 Mar 2025: PFHxS 0.002, PFOA 0.001
  10. 9 Apr 2025: PFHxS 0.002, PFOA 0.002
  11. 8 May 2025: PFOS 0.001, PFHxS 0.002
  12. 4 Jun 2025: not detected
  13. 11 Jun 2025: PFHxS 0.001
  14. 10 Jul 2025: PFHxS 0.001

5 Aug 2025 to 5 Aug 2026

  1. 5 Aug 2025: not detected
  2. 7 Aug 2025: PFHxS 0.001
  3. 16 Sep 2025: PFOS 0.002, PFHxS 0.004, PFBS 0.001
  4. 8 Oct 2025: PFOS 0.001, PFHxS 0.003
  5. 13 Nov 2025: PFOS 0.002, PFHxS 0.006, PFOA 0.001
  6. 9 Dec 2025: PFOS 0.003, PFHxS 0.004
  7. 7 Jan 2026: PFOS 0.002, PFHxS 0.002
  8. 4 Feb 2026: PFHxS 0.002
  9. 11 Mar 2026: not detected
  10. 15 Apr 2026: PFHxS 0.002
  11. 13 May 2026: PFOS 0.002, PFHxS 0.004, PFBS 0.001
  12. 10 Jun 2026: PFOS 0.002, PFHxS 0.004
  13. 7 Jul 2026: PFOS 0.002, PFHxS 0.002, PFBS 0.001
  14. 5 Aug 2026: PFOS 0.002, PFHxS 0.002, PFBS 0.001

PFAS detected, below guideline valuesNothing detected

Detected on 24 of 28 dates; nothing detected on 4.

Every site 6 result in Council’s Ourimbah Creek catchment PFAS monitoring results, August 2024 to August 2026, micrograms per litre, with a detection limit of 0.001. The counts are ours, from Council’s table.

We cannot tell from the documents whether the officers meant a different sampling point, a different test or a different period, and we have not asked Council. The officers’ wider point survives either way, since every site 6 result is below the guideline values. But “below detection limits” and “detected on 24 of 28 dates” are different statements, and the agenda councillors voted on carried only the first.

Mardi Dam, where the resolution looks next

Council’s results for the Mardi Dam catchment list 12 results from December 2024 to August 2026, two of them at the dam’s Wyong River and Ourimbah Creek inlets. Eleven are nil detection. The exception is 11 August 2026: PFOS at 0.002 micrograms per litre, which Council notes as below the guideline level. A resample eight days later found nothing: Nil detected in resample.

Mardi Dam catchment results, December 2024 to August 2026

  • The dam, 8 samples, 2 Dec 2024 to 5 May 2026N/D
  • Wyong River and Ourimbah Creek inletsN/D
  • The dam, 11 Aug 2026PFOS 0.002
  • The dam, 19 Aug 2026, resampleN/D

Micrograms per litre. N/D is nil detection at a 0.001 limit. The two inlet samples carry no date of their own in the table.

From Council’s Mardi Dam catchment PFAS monitoring results, August 2024 to August 2026. Grouping is ours; every result is Council’s.

Water samples show what is in the water on the day. The resolution’s interest is the dam floor, and the cores in part 5 are a question about time: whether anything there settled recently or long ago, which tells you whether a source is still active.

Our view

Councillors were right to keep Mardi Dam in the resolution, and right to keep the expert-advice alternative in it. The dam is a source water Council monitors, its only detection in the listed results came in August, and the alternative lets Council get scoping advice before it pays for cores. The officers’ caution about cost is fair, and the alternative answers it. The harder question is the pump station sentence. The agenda told councillors PFAS was below detection limits at the extraction point; Council’s published table records detections there on 24 of 28 dates, every one below the guideline values. The report the resolution asks for should reconcile the two, in public, because the people most exposed to the gap are the households taking water from the creek.

What happens next

The resolution asks for a report back on agency responses, any fish and yabby investigations and any Mardi Dam sediment investigation, and to make that information publicly available. It sets no date. The next Ordinary Council meeting is on 27 October, when two notices of motion deferred from this meeting return. We will check each Ordinary Council agenda for the PFAS report and report what it shows when it is listed.

  1. 5 August 2026 Council samples 13 Ourimbah Creek catchment sites; its notes put five above a guideline value.
  2. 11 August 2026 PFOS at 0.002 micrograms per litre in Mardi Dam, below the guideline level.
  3. 15 August 2026 The Ourimbah Valley PFAS Community Meeting, whose presentations the resolution sends to State agencies.
  4. 19 August 2026 Mardi Dam resample: nil detected.
  5. 29 September 2026 At the adjourned sitting of the 22 September meeting, the motion carries 14 to 1.
  6. 9 October 2026 The minutes are published to Council’s business papers portal.
  7. 27 October 2026 Next Ordinary Council meeting.

Sources: Ourimbah Creek and Mardi Dam catchment monitoring results; minutes of 22 September 2026, pages 39 to 43 (resolutions C-26/1161 and C-26/1162); the portal’s record of the minutes’ upload.