Water hardness and quality in Preston
Page updated · Report periods are shown with each report.
Lancashire · North West. Explore the published supply-area report and check your postcode for a supplier-confirmed match.
Example postcode: PR1 2PP · Supplier-confirmed source area: United Utilities zone “Preston Central”. This is an example supply area: zone names are the supplier’s own labels and may refer to works or places outside Preston. Other addresses may have a different supply.
Confirm your address · Check a postcode
A town can span several supply areas. Enter your full postcode to check which supplier and source area serve your address. Matching covers selected suppliers; unsupported areas remain clearly identified.
Your water at a glance
Soft water. Know your mineral level.
This figure helps you choose appliance settings. Hardness describes dissolved minerals and does not establish whether every water-quality requirement was met.
85 mg/l as CaCO₃
Soft ≤100 · Slightly hard ≤150 · Moderately hard ≤200 · Hard ≤300 · Very hard >300 mg/l. DWI hardness bands; not safety grades.
Published quality checks
1 parameter needs a closer look
These labels describe Rolling 12 months; updated 2026-09-11. 57 other parameters have no complete compliance judgement here. They are not a guarantee about an individual tap today.
Coliform bacteria
Understand the reported results ↓Read the supplier’s original report and notes ↗Make this useful for your home
Hardness reporting period: Rolling 12 months; updated 2026-09-11 · Quality reporting period: Rolling 12 months; updated 2026-09-11
Appliance settings · Convert hardness units
0.85 mmol/l
A conversion of the published hardness, not another test. Follow your appliance’s model-specific instructions.
Drinking-water results
What do the important results mean?
Read the status, sample range and source requirement together. A low average can hide an individual exceedance. Green labels mean the supplier reported no exceedances for that parameter and period; amber calls for source context.
Coliform bacteria
! Range crosses the source reference
Published mean
0 number/100ml
Source reference: 0 number/100ml
Used to monitor water-system hygiene. Interpret detections with the supplier’s sampling location and investigation notes.
104 samples · Range: 0 to 2 number/100ml
The reported sample range extends beyond the numerical reference. Check the source explanation; no failure count is inferred.
E. coli
Mean at or below the source limit
Published mean
0 number/100ml
Source reference: 0 number/100ml
A microbiological indicator. The reported sample results and any failures matter more than an average bacterial count.
104 samples · Range: 0 to 0 number/100ml
Compliance detail is unavailable. This summary alone does not establish that every sample complied.
Lead
Reported upper bound at or below the limit
Published mean
<0.550 µg Pb/l
Source reference: 10 µg Pb/l
Plumbing can affect lead at an individual tap. An area average cannot rule out a problem with pipes at your property.
7 samples · Range: <0.550 to <0.550 µg Pb/l
Compliance detail is unavailable. This summary alone does not establish that every sample complied.
“<” is part of the source result. It is not an exact concentration or a measured zero.
Nitrate
Reported upper bound at or below the limit
Published mean
<2.36 mg NO3/l
Source reference: 50 mg NO3/l
A dissolved compound monitored against drinking-water requirements. Its mean, highest reported result and sample count answer different questions.
9 samples · Range: <2.04 to 3.10 mg NO3/l
Compliance detail is unavailable. This summary alone does not establish that every sample complied.
“<” is part of the source result. It is not an exact concentration or a measured zero.
For your household
What should you do next?
Check appliance settings
Match the hardness unit to your dishwasher manual. Settings depend on the model.
Dishwasher guideUnderstand treatment options
A filter and a softener do different jobs. Start with the household problem you want to solve.
Filters and limescaleA new change at your tap?
For a new taste, smell, colour or supply problem, check current supplier advice. Annual data is not a live incident feed.
Official supplier help ↗Taste, appearance and mineral content
Chlorine, pH and minerals answer different questions. Calcium and magnesium help describe hardness; chloride is different from treatment chlorine. None is a stand-alone water-quality score.
Free chlorine residual
Disinfectant remaining after treatment. It can influence taste and smell; a lower concentration is not automatically better.
See the measurement and context ↓pH
Describes acidity and alkalinity on a scale, rather than an amount of a substance. Where the source gives a range, both its lower and upper bounds matter.
See the measurement and context ↓Calcium
A naturally occurring mineral that contributes to hardness. Calcium alone is not the same measurement as total hardness.
See the measurement and context ↓Has the hardness changed?
History for this reported source area. Only comparable annual statistics appear in the chart; rolling summaries are kept separate. These are not daily tests at your address.
A comparable historical series is not available yet. We will add earlier reports when we can verify their periods and source areas.
Explore all measurements · 61 parameters · Rolling 12 months; updated 2026-09-11
Every result retains its original units, range, sample count and source notes. Comparisons use the reference printed in this report; qualitative references and missing limits are not converted into invented pass/fail judgements. Unlisted substances are not necessarily absent from the water.
Parameters without their own explanation: A substance monitored in this supplier report. The source reference, units, sample range and any reported failures provide its context; the number alone is not a water-quality rating.
Source note on 60 of these parameters: “Supplier reports 0% of samples failing its requirement. This is a historical percentage, not a current incident or a reconstructed failure count.”
Hardness and minerals 8 parameters
Alkalinity
No numerical limit supplied
Published mean
26.6 mg/l
Source reference:
How strongly water resists a change in acidity. This helps describe its chemistry; it is different from pH and total hardness.
10 samples · Range: 17.5 to 54.0 mg/l
This report gives no numerical limit for this parameter. A higher or lower number is not automatically better.
Original wording and source notes
Source reference: . Source parameter: Alkalinity as CaCO3. Original mean: 26.6 mg/l.
Source note: printed once above this list (the same note appears on 60 parameters).
Calcium
No numerical limit supplied
Published mean
27.4 mg Ca/l
Source reference:
A naturally occurring mineral that contributes to hardness. Calcium alone is not the same measurement as total hardness.
34 samples · Range: 14.7 to 45.6 mg Ca/l
This report gives no numerical limit for this parameter. A higher or lower number is not automatically better.
Original wording and source notes
Source reference: . Source parameter: Calcium. Original mean: 27.4 mg Ca/l.
Source note: printed once above this list (the same note appears on 60 parameters).
Chloride
Reported upper bound at or below the limit
Published mean
<15.6 mg Cl/l
Source reference: 250 mg Cl/l
A dissolved salt component that can influence taste at higher concentrations. It is different from chlorine used in treatment.
72 samples · Range: <12.3 to <32.8 mg Cl/l
Compliance detail is unavailable. This summary alone does not establish that every sample complied.
“<” is part of the source result. It is not an exact concentration or a measured zero.
Original wording and source notes
Source reference: 250. Source parameter: Chloride. Original mean: <15.6 mg Cl/l.
Source note: printed once above this list (the same note appears on 60 parameters).
Fluoride
Reported upper bound at or below the limit
Published mean
<0.270 mg F/l
Source reference: 1.5 mg F/l
Can occur naturally or be added through a fluoridation scheme. The concentration alone does not tell you whether it was added; a lower number is not automatically better.
156 samples · Range: <0.270 to <0.270 mg F/l
Compliance detail is unavailable. This summary alone does not establish that every sample complied.
“<” is part of the source result. It is not an exact concentration or a measured zero.
Original wording and source notes
Source reference: 1.5. Source parameter: Fluoride. Original mean: <0.270 mg F/l.
Source note: printed once above this list (the same note appears on 60 parameters).
Total hardness
No numerical limit supplied
Published mean
85 mg CaCO3/l
Source reference:
Dissolved calcium and magnesium affect limescale and appliance settings. This is a mineral description, not a safety score.
34 samples · Range: 42 to 153 mg CaCO3/l
This report gives no numerical limit for this parameter. A higher or lower number is not automatically better.
Original wording and source notes
Source reference: . Source parameter: Hardness Total as CaCO3. Original mean: 85 mg CaCO3/l.
Source note: printed once above this list (the same note appears on 60 parameters).
Magnesium
No numerical limit supplied
Published mean
4.10 mg Mg/l
Source reference:
A naturally occurring mineral that contributes to hardness alongside calcium.
34 samples · Range: 1.09 to 10.0 mg Mg/l
This report gives no numerical limit for this parameter. A higher or lower number is not automatically better.
Original wording and source notes
Source reference: . Source parameter: Magnesium. Original mean: 4.10 mg Mg/l.
Source note: printed once above this list (the same note appears on 60 parameters).
Sodium
Mean at or below the source limit
Published mean
14.8 mg Na/l
Source reference: 200 mg Na/l
A dissolved salt component. Compare the water measurement with its source reference; it is not a measure of your total dietary salt intake.
9 samples · Range: 6.04 to 28.4 mg Na/l
Compliance detail is unavailable. This summary alone does not establish that every sample complied.
Original wording and source notes
Source reference: 200. Source parameter: Sodium. Original mean: 14.8 mg Na/l.
Source note: printed once above this list (the same note appears on 60 parameters).
Sulphate
Mean at or below the source limit
Published mean
39.5 mg SO4/l
Source reference: 250 mg SO4/l
A dissolved mineral component monitored in water-quality reports. Read its concentration alongside the source reference.
78 samples · Range: 5.13 to 112 mg SO4/l
Compliance detail is unavailable. This summary alone does not establish that every sample complied.
Original wording and source notes
Source reference: 250. Source parameter: Sulphate. Original mean: 39.5 mg SO4/l.
Source note: printed once above this list (the same note appears on 60 parameters).
Taste, appearance and treatment 6 parameters
Free chlorine residual
No numerical limit supplied
Published mean
0.69 mg/l
Source reference:
Disinfectant remaining after treatment. It can influence taste and smell; a lower concentration is not automatically better.
102 samples · Range: 0.15 to 1.10 mg/l
This report gives no numerical limit for this parameter. A higher or lower number is not automatically better.
Original wording and source notes
Source reference: . Source parameter: Residual chlorine - Free. Original mean: 0.69 mg/l.
Source note: printed once above this list (the same note appears on 60 parameters).
Colour
Reported upper bound at or below the limit
Published mean
<1.92 mg/l Pt/Co scale
Source reference: 20 mg/l Pt/Co scale
A measure of water colour under test conditions. A new change at your tap should be checked with your supplier.
32 samples · Range: <1.75 to <2.08 mg/l Pt/Co scale
Compliance detail is unavailable. This summary alone does not establish that every sample complied.
“<” is part of the source result. It is not an exact concentration or a measured zero.
Original wording and source notes
Source reference: 20. Source parameter: Colour. Original mean: <1.92 mg/l Pt/Co scale.
Source note: printed once above this list (the same note appears on 60 parameters).
Conductivity
Mean at or below the source limit
Published mean
209 uS/cm at 20oC
Source reference: 2500 uS/cm at 20oC
Indicates how readily water conducts electricity, influenced by dissolved ions. It is not a direct measurement of hardness or safety.
32 samples · Range: 107 to 373 uS/cm at 20oC
Compliance detail is unavailable. This summary alone does not establish that every sample complied.
Original wording and source notes
Source reference: 2500. Source parameter: Conductivity. Original mean: 209 uS/cm at 20oC.
Source note: printed once above this list (the same note appears on 60 parameters).
Total organic carbon
No numerical limit supplied
Published mean
1.10 mg C/l
Source reference:
A broad measure of organic carbon used to understand water and treatment. It does not identify an individual contaminant.
74 samples · Range: 0.610 to 2.20 mg C/l
This report gives no numerical limit for this parameter. A higher or lower number is not automatically better.
Original wording and source notes
Source reference: . Source parameter: Total organic carbon. Original mean: 1.10 mg C/l.
Source note: printed once above this list (the same note appears on 60 parameters).
pH
Reference needs source context
Published mean
7.36 pH value
Source reference: 9.5
Describes acidity and alkalinity on a scale, rather than an amount of a substance. Where the source gives a range, both its lower and upper bounds matter.
68 samples · Range: 7.01 to 7.90 pH value
The supplied reference cannot be safely compared numerically with this reading. Check its units and the complete source requirement; no pass/fail judgement is inferred.
Original wording and source notes
Source reference: 9.5. Source parameter: Hydrogen ion (pH). Original mean: 7.36 pH value.
Source note: printed once above this list (the same note appears on 60 parameters).
Turbidity
Reported upper bound at or below the limit
Published mean
<0.17 NTU
Source reference: 4 NTU
Measures cloudiness caused by suspended particles. It cannot identify their cause on its own.
32 samples · Range: <0.10 to <0.20 NTU
Compliance detail is unavailable. This summary alone does not establish that every sample complied.
“<” is part of the source result. It is not an exact concentration or a measured zero.
Original wording and source notes
Source reference: 4. Source parameter: Turbidity. Original mean: <0.17 NTU.
Source note: printed once above this list (the same note appears on 60 parameters).
Metals 13 parameters
Aluminium
Reported upper bound at or below the limit
Published mean
<5.74 µg Al/l
Source reference: 200 µg Al/l
Monitored as part of water-quality testing and treatment control. Compare with the reference and sample results in the source.
34 samples · Range: <2.71 to 9.02 µg Al/l
Compliance detail is unavailable. This summary alone does not establish that every sample complied.
“<” is part of the source result. It is not an exact concentration or a measured zero.
Original wording and source notes
Source reference: 200. Source parameter: Aluminium. Original mean: <5.74 µg Al/l.
Source note: printed once above this list (the same note appears on 60 parameters).
Antimony
Reported upper bound at or below the limit
Published mean
<0.320 µg Sb/l
Source reference: 5 µg Sb/l
A trace element monitored in drinking water. The source reference and sample results provide the relevant comparison.
8 samples · Range: <0.310 to <0.330 µg Sb/l
Compliance detail is unavailable. This summary alone does not establish that every sample complied.
“<” is part of the source result. It is not an exact concentration or a measured zero.
Original wording and source notes
Source reference: 5. Source parameter: Antimony. Original mean: <0.320 µg Sb/l.
Source note: printed once above this list (the same note appears on 60 parameters).
Arsenic
Reported upper bound at or below the limit
Published mean
<0.480 µg As/l
Source reference: 10 µg As/l
A trace element monitored against a drinking-water requirement. Use the source results and units rather than taste or appearance to interpret it.
8 samples · Range: <0.480 to <0.480 µg As/l
Compliance detail is unavailable. This summary alone does not establish that every sample complied.
“<” is part of the source result. It is not an exact concentration or a measured zero.
Original wording and source notes
Source reference: 10. Source parameter: Arsenic. Original mean: <0.480 µg As/l.
Source note: printed once above this list (the same note appears on 60 parameters).
Boron
Reported upper bound at or below the limit
Published mean
<0.0177 mg B/l
Source reference: 1 mg B/l
A dissolved element monitored in drinking water. The source reference applies to the parameter and units shown here.
75 samples · Range: <0.0127 to <0.0199 mg B/l
Compliance detail is unavailable. This summary alone does not establish that every sample complied.
“<” is part of the source result. It is not an exact concentration or a measured zero.
Original wording and source notes
Source reference: 1. Source parameter: Boron. Original mean: <0.0177 mg B/l.
Source note: printed once above this list (the same note appears on 60 parameters).
Cadmium
Reported upper bound at or below the limit
Published mean
<0.0900 µg Cd/l
Source reference: 5 µg Cd/l
A trace metal monitored in drinking water. A less-than result reports an upper bound, not a measured zero.
8 samples · Range: <0.0900 to <0.0900 µg Cd/l
Compliance detail is unavailable. This summary alone does not establish that every sample complied.
“<” is part of the source result. It is not an exact concentration or a measured zero.
Original wording and source notes
Source reference: 5. Source parameter: Cadmium. Original mean: <0.0900 µg Cd/l.
Source note: printed once above this list (the same note appears on 60 parameters).
Chromium
Reported upper bound at or below the limit
Published mean
<0.830 µg Cr/l
Source reference: 50 µg Cr/l
A trace metal monitored in drinking-water reports. Keep the source’s chemical definition and units when comparing results.
8 samples · Range: <0.830 to <0.830 µg Cr/l
Compliance detail is unavailable. This summary alone does not establish that every sample complied.
“<” is part of the source result. It is not an exact concentration or a measured zero.
Original wording and source notes
Source reference: 50. Source parameter: Chromium. Original mean: <0.830 µg Cr/l.
Source note: printed once above this list (the same note appears on 60 parameters).
Copper
Reported upper bound at or below the limit
Published mean
<0.0284 mg Cu/l
Source reference: 2 mg Cu/l
Can be influenced by plumbing. The area report does not replace investigation of a problem at an individual property.
7 samples · Range: <0.0104 to 0.0787 mg Cu/l
Compliance detail is unavailable. This summary alone does not establish that every sample complied.
“<” is part of the source result. It is not an exact concentration or a measured zero.
Original wording and source notes
Source reference: 2. Source parameter: Copper. Original mean: <0.0284 mg Cu/l.
Source note: printed once above this list (the same note appears on 60 parameters).
Iron
Reported upper bound at or below the limit
Published mean
<12.0 µg Fe/l
Source reference: 200 µg Fe/l
Can affect water colour, staining and taste. A historical result does not diagnose a change in your tap water today.
34 samples · Range: 3.30 to 57.0 µg Fe/l
Compliance detail is unavailable. This summary alone does not establish that every sample complied.
“<” is part of the source result. It is not an exact concentration or a measured zero.
Original wording and source notes
Source reference: 200. Source parameter: Iron. Original mean: <12.0 µg Fe/l.
Source note: printed once above this list (the same note appears on 60 parameters).
Lead
Reported upper bound at or below the limit
Published mean
<0.550 µg Pb/l
Source reference: 10 µg Pb/l
Plumbing can affect lead at an individual tap. An area average cannot rule out a problem with pipes at your property.
7 samples · Range: <0.550 to <0.550 µg Pb/l
Compliance detail is unavailable. This summary alone does not establish that every sample complied.
“<” is part of the source result. It is not an exact concentration or a measured zero.
Original wording and source notes
Source reference: 10. Source parameter: Lead. Original mean: <0.550 µg Pb/l.
Source note: printed once above this list (the same note appears on 60 parameters).
Manganese
Reported upper bound at or below the limit
Published mean
<0.544 µg Mn/l
Source reference: 50 µg Mn/l
Can affect colour and deposits. Any reported exceedance needs the supplier’s investigation context.
34 samples · Range: <0.370 to 1.40 µg Mn/l
Compliance detail is unavailable. This summary alone does not establish that every sample complied.
“<” is part of the source result. It is not an exact concentration or a measured zero.
Original wording and source notes
Source reference: 50. Source parameter: Manganese. Original mean: <0.544 µg Mn/l.
Source note: printed once above this list (the same note appears on 60 parameters).
Mercury
Reported upper bound at or below the limit
Published mean
<0.130 µg Hg/l
Source reference: 1 µg Hg/l
A trace metal monitored against drinking-water requirements. Keep detection limits separate from exact measurements.
74 samples · Range: <0.130 to <0.130 µg Hg/l
Compliance detail is unavailable. This summary alone does not establish that every sample complied.
“<” is part of the source result. It is not an exact concentration or a measured zero.
Original wording and source notes
Source reference: 1. Source parameter: Mercury. Original mean: <0.130 µg Hg/l.
Source note: printed once above this list (the same note appears on 60 parameters).
Nickel
Reported upper bound at or below the limit
Published mean
<0.863 µg Ni/l
Source reference: 20 µg Ni/l
A monitored metal that can be influenced by materials in contact with water. Local plumbing and sampling context matter.
7 samples · Range: <0.770 to 1.34 µg Ni/l
Compliance detail is unavailable. This summary alone does not establish that every sample complied.
“<” is part of the source result. It is not an exact concentration or a measured zero.
Original wording and source notes
Source reference: 20. Source parameter: Nickel. Original mean: <0.863 µg Ni/l.
Source note: printed once above this list (the same note appears on 60 parameters).
Selenium
Reported upper bound at or below the limit
Published mean
<0.850 µg Se/l
Source reference: 10 µg Se/l
A trace element monitored in drinking water. Its presence alone does not establish that a requirement was exceeded.
8 samples · Range: <0.850 to <0.850 µg Se/l
Compliance detail is unavailable. This summary alone does not establish that every sample complied.
“<” is part of the source result. It is not an exact concentration or a measured zero.
Original wording and source notes
Source reference: 10. Source parameter: Selenium. Original mean: <0.850 µg Se/l.
Source note: printed once above this list (the same note appears on 60 parameters).
Microbiology 3 parameters
Coliform bacteria
! Range crosses the source reference
Published mean
0 number/100ml
Source reference: 0 number/100ml
Used to monitor water-system hygiene. Interpret detections with the supplier’s sampling location and investigation notes.
104 samples · Range: 0 to 2 number/100ml
The reported sample range extends beyond the numerical reference. Check the source explanation; no failure count is inferred.
Original wording and source notes
Source reference: 0. Source parameter: Coliform bacteria. Original mean: 0 number/100ml.
Supplier reports 0.96% of samples failing its requirement. This is a historical percentage, not a current incident or a reconstructed failure count.
E. coli
Mean at or below the source limit
Published mean
0 number/100ml
Source reference: 0 number/100ml
A microbiological indicator. The reported sample results and any failures matter more than an average bacterial count.
104 samples · Range: 0 to 0 number/100ml
Compliance detail is unavailable. This summary alone does not establish that every sample complied.
Original wording and source notes
Source reference: 0. Source parameter: E.coli. Original mean: 0 number/100ml.
Source note: printed once above this list (the same note appears on 60 parameters).
Enterococci
Mean at or below the source limit
Published mean
0 number/100ml
Source reference: 0 number/100ml
A microbiological indicator assessed through sample results. Read any reported failures with the supplier’s investigation notes.
7 samples · Range: 0 to 0 number/100ml
Compliance detail is unavailable. This summary alone does not establish that every sample complied.
Original wording and source notes
Source reference: 0. Source parameter: Enterococci. Original mean: 0 number/100ml.
Source note: printed once above this list (the same note appears on 60 parameters).
Other monitored substances 31 parameters
2,4-D
Reported upper bound at or below the limit
Published mean
<0.0090 µg/l
Source reference: 0.1 µg/l
About this parameter: see the note above this list.
25 samples · Range: <0.0090 to <0.0090 µg/l
Compliance detail is unavailable. This summary alone does not establish that every sample complied.
“<” is part of the source result. It is not an exact concentration or a measured zero.
Original wording and source notes
Source reference: 0.1. Source parameter: 2,4-D. Original mean: <0.0090 µg/l.
Source note: printed once above this list (the same note appears on 60 parameters).
Ammonium (ammonia and ammonium ions)
Reported upper bound at or below the limit
Published mean
<0.0409 mg NH4/l
Source reference: 0.5 mg NH4/l
About this parameter: see the note above this list.
10 samples · Range: <0.0322 to <0.0540 mg NH4/l
Compliance detail is unavailable. This summary alone does not establish that every sample complied.
“<” is part of the source result. It is not an exact concentration or a measured zero.
Original wording and source notes
Source reference: 0.5. Source parameter: Ammonium (ammonia and ammonium ions). Original mean: <0.0409 mg NH4/l.
Source note: printed once above this list (the same note appears on 60 parameters).
Asulam
Reported upper bound at or below the limit
Published mean
<0.0103 µg/l
Source reference: 0.1 µg/l
About this parameter: see the note above this list.
25 samples · Range: <0.0042 to <0.0170 µg/l
Compliance detail is unavailable. This summary alone does not establish that every sample complied.
“<” is part of the source result. It is not an exact concentration or a measured zero.
Original wording and source notes
Source reference: 0.1. Source parameter: Asulam. Original mean: <0.0103 µg/l.
Source note: printed once above this list (the same note appears on 60 parameters).
Benzene
Reported upper bound at or below the limit
Published mean
<0.0812 µg/l
Source reference: 1 µg/l
About this parameter: see the note above this list.
73 samples · Range: <0.0780 to <0.0830 µg/l
Compliance detail is unavailable. This summary alone does not establish that every sample complied.
“<” is part of the source result. It is not an exact concentration or a measured zero.
Original wording and source notes
Source reference: 1. Source parameter: Benzene. Original mean: <0.0812 µg/l.
Source note: printed once above this list (the same note appears on 60 parameters).
Benzo(a)pyrene
Reported upper bound at or below the limit
Published mean
<0.0020 µg/l
Source reference: 0.01 µg/l
About this parameter: see the note above this list.
7 samples · Range: <0.0020 to <0.0020 µg/l
Compliance detail is unavailable. This summary alone does not establish that every sample complied.
“<” is part of the source result. It is not an exact concentration or a measured zero.
Original wording and source notes
Source reference: 0.01. Source parameter: Benzo(a)pyrene. Original mean: <0.0020 µg/l.
Source note: printed once above this list (the same note appears on 60 parameters).
Bromate
Reported upper bound at or below the limit
Published mean
<0.746 µg BrO3/l
Source reference: 10 µg BrO3/l
About this parameter: see the note above this list.
7 samples · Range: <0.640 to <1.01 µg BrO3/l
Compliance detail is unavailable. This summary alone does not establish that every sample complied.
“<” is part of the source result. It is not an exact concentration or a measured zero.
Original wording and source notes
Source reference: 10. Source parameter: Bromate. Original mean: <0.746 µg BrO3/l.
Source note: printed once above this list (the same note appears on 60 parameters).
Residual chlorine - Total
No numerical limit supplied
Published mean
0.77 mg/l
Source reference:
About this parameter: see the note above this list.
101 samples · Range: 0.26 to 1.35 mg/l
This report gives no numerical limit for this parameter. A higher or lower number is not automatically better.
Original wording and source notes
Source reference: . Source parameter: Residual chlorine - Total. Original mean: 0.77 mg/l.
Source note: printed once above this list (the same note appears on 60 parameters).
Colony counts after 3 days at 22 deg C
No numerical limit supplied
Published mean
3 number/1ml
Source reference:
About this parameter: see the note above this list.
40 samples · Range: 0 to 76 number/1ml
This report gives no numerical limit for this parameter. A higher or lower number is not automatically better.
Original wording and source notes
Source reference: . Source parameter: Colony counts after 3 days at 22 deg C. Original mean: 3 number/1ml.
Source note: printed once above this list (the same note appears on 60 parameters).
Clostridium perfringens (including spores)
Mean at or below the source limit
Published mean
0 number/100ml
Source reference: 0 number/100ml
About this parameter: see the note above this list.
7 samples · Range: 0 to 0 number/100ml
Compliance detail is unavailable. This summary alone does not establish that every sample complied.
Original wording and source notes
Source reference: 0. Source parameter: Clostridium perfringens (including spores). Original mean: 0 number/100ml.
Source note: printed once above this list (the same note appears on 60 parameters).
Clopyralid
Reported upper bound at or below the limit
Published mean
<0.0150 µg/l
Source reference: 0.1 µg/l
About this parameter: see the note above this list.
25 samples · Range: <0.0150 to <0.0150 µg/l
Compliance detail is unavailable. This summary alone does not establish that every sample complied.
“<” is part of the source result. It is not an exact concentration or a measured zero.
Original wording and source notes
Source reference: 0.1. Source parameter: Clopyralid. Original mean: <0.0150 µg/l.
Source note: printed once above this list (the same note appears on 60 parameters).
Cyanide
Reported upper bound at or below the limit
Published mean
<3.91 µg CN/l
Source reference: 50 µg CN/l
About this parameter: see the note above this list.
67 samples · Range: <3.91 to <3.91 µg CN/l
Compliance detail is unavailable. This summary alone does not establish that every sample complied.
“<” is part of the source result. It is not an exact concentration or a measured zero.
Original wording and source notes
Source reference: 50. Source parameter: Cyanide. Original mean: <3.91 µg CN/l.
Source note: printed once above this list (the same note appears on 60 parameters).
1,2-dichloroethane
Reported upper bound at or below the limit
Published mean
<0.162 µg/l
Source reference: 3 µg/l
About this parameter: see the note above this list.
73 samples · Range: <0.130 to <0.180 µg/l
Compliance detail is unavailable. This summary alone does not establish that every sample complied.
“<” is part of the source result. It is not an exact concentration or a measured zero.
Original wording and source notes
Source reference: 3. Source parameter: 1,2-dichloroethane. Original mean: <0.162 µg/l.
Source note: printed once above this list (the same note appears on 60 parameters).
Diazinon
Reported upper bound at or below the limit
Published mean
<0.0083 µg/l
Source reference: 0.1 µg/l
About this parameter: see the note above this list.
27 samples · Range: <0.0070 to <0.0090 µg/l
Compliance detail is unavailable. This summary alone does not establish that every sample complied.
“<” is part of the source result. It is not an exact concentration or a measured zero.
Original wording and source notes
Source reference: 0.1. Source parameter: Diazinon. Original mean: <0.0083 µg/l.
Source note: printed once above this list (the same note appears on 60 parameters).
Dicamba
Reported upper bound at or below the limit
Published mean
<0.0157 µg/l
Source reference: 0.1 µg/l
About this parameter: see the note above this list.
25 samples · Range: <0.0120 to <0.0160 µg/l
Compliance detail is unavailable. This summary alone does not establish that every sample complied.
“<” is part of the source result. It is not an exact concentration or a measured zero.
Original wording and source notes
Source reference: 0.1. Source parameter: Dicamba. Original mean: <0.0157 µg/l.
Source note: printed once above this list (the same note appears on 60 parameters).
Dichlorprop
Reported upper bound at or below the limit
Published mean
<0.0099 µg/l
Source reference: 0.1 µg/l
About this parameter: see the note above this list.
25 samples · Range: <0.0090 to <0.0100 µg/l
Compliance detail is unavailable. This summary alone does not establish that every sample complied.
“<” is part of the source result. It is not an exact concentration or a measured zero.
Original wording and source notes
Source reference: 0.1. Source parameter: Dichlorprop. Original mean: <0.0099 µg/l.
Source note: printed once above this list (the same note appears on 60 parameters).
Diuron
Reported upper bound at or below the limit
Published mean
<0.0111 µg/l
Source reference: 0.1 µg/l
About this parameter: see the note above this list.
25 samples · Range: <0.0100 to <0.0130 µg/l
Compliance detail is unavailable. This summary alone does not establish that every sample complied.
“<” is part of the source result. It is not an exact concentration or a measured zero.
Original wording and source notes
Source reference: 0.1. Source parameter: Diuron. Original mean: <0.0111 µg/l.
Source note: printed once above this list (the same note appears on 60 parameters).
Fluroxypyr
Reported upper bound at or below the limit
Published mean
<0.0230 µg/l
Source reference: 0.1 µg/l
About this parameter: see the note above this list.
25 samples · Range: <0.0230 to <0.0230 µg/l
Compliance detail is unavailable. This summary alone does not establish that every sample complied.
“<” is part of the source result. It is not an exact concentration or a measured zero.
Original wording and source notes
Source reference: 0.1. Source parameter: Fluroxypyr. Original mean: <0.0230 µg/l.
Source note: printed once above this list (the same note appears on 60 parameters).
Glyphosate
Reported upper bound at or below the limit
Published mean
<0.0196 µg/l
Source reference: 0.1 µg/l
About this parameter: see the note above this list.
25 samples · Range: <0.0170 to <0.0200 µg/l
Compliance detail is unavailable. This summary alone does not establish that every sample complied.
“<” is part of the source result. It is not an exact concentration or a measured zero.
Original wording and source notes
Source reference: 0.1. Source parameter: Glyphosate. Original mean: <0.0196 µg/l.
Source note: printed once above this list (the same note appears on 60 parameters).
MCPA
Reported upper bound at or below the limit
Published mean
<0.0107 µg/l
Source reference: 0.1 µg/l
About this parameter: see the note above this list.
29 samples · Range: <0.0100 to 0.0200 µg/l
Compliance detail is unavailable. This summary alone does not establish that every sample complied.
“<” is part of the source result. It is not an exact concentration or a measured zero.
Original wording and source notes
Source reference: 0.1. Source parameter: MCPA. Original mean: <0.0107 µg/l.
Source note: printed once above this list (the same note appears on 60 parameters).
Mecoprop
Reported upper bound at or below the limit
Published mean
<0.0100 µg/l
Source reference: 0.1 µg/l
About this parameter: see the note above this list.
25 samples · Range: <0.0100 to <0.0100 µg/l
Compliance detail is unavailable. This summary alone does not establish that every sample complied.
“<” is part of the source result. It is not an exact concentration or a measured zero.
Original wording and source notes
Source reference: 0.1. Source parameter: Mecoprop. Original mean: <0.0100 µg/l.
Source note: printed once above this list (the same note appears on 60 parameters).
Nitrite
Reported upper bound at or below the limit
Published mean
<0.0082 mg NO2/l
Source reference: 0.5 mg NO2/l
A nitrogen compound monitored in water supplies. Requirements can depend on where the sample was collected; use the reference printed in this report.
9 samples · Range: <0.0076 to <0.0099 mg NO2/l
Compliance detail is unavailable. This summary alone does not establish that every sample complied.
“<” is part of the source result. It is not an exact concentration or a measured zero.
Original wording and source notes
Source reference: 0.5. Source parameter: Nitrite. Original mean: <0.0082 mg NO2/l.
Source note: printed once above this list (the same note appears on 60 parameters).
Nitrate
Reported upper bound at or below the limit
Published mean
<2.36 mg NO3/l
Source reference: 50 mg NO3/l
A dissolved compound monitored against drinking-water requirements. Its mean, highest reported result and sample count answer different questions.
9 samples · Range: <2.04 to 3.10 mg NO3/l
Compliance detail is unavailable. This summary alone does not establish that every sample complied.
“<” is part of the source result. It is not an exact concentration or a measured zero.
Original wording and source notes
Source reference: 50. Source parameter: Nitrate. Original mean: <2.36 mg NO3/l.
Source note: printed once above this list (the same note appears on 60 parameters).
(Nitrate)/50 plus (nitrite)/3
Mean at or below the source limit
Published mean
0.0384 mg/l
Source reference: 1 mg/l
About this parameter: see the note above this list.
9 samples · Range: 0.0230 to 0.0610 mg/l
Compliance detail is unavailable. This summary alone does not establish that every sample complied.
Original wording and source notes
Source reference: 1. Source parameter: (Nitrate)/50 plus (nitrite)/3. Original mean: 0.0384 mg/l.
Source note: printed once above this list (the same note appears on 60 parameters).
Odour (quantitative)
Mean at or below the source limit
Published mean
0 dilution number at 25oC
Source reference: 0 dilution number at 25oC
About this parameter: see the note above this list.
47 samples · Range: 0 to 0 dilution number at 25oC
Compliance detail is unavailable. This summary alone does not establish that every sample complied.
Original wording and source notes
Source reference: 0. Source parameter: Odour (quantitative). Original mean: 0 dilution number at 25oC.
Source note: printed once above this list (the same note appears on 60 parameters).
Polycyclic aromatic hydrocarbons (sum of 4 PAHs)
Mean at or below the source limit
Published mean
0.0000 µg/l
Source reference: 0.1 µg/l
About this parameter: see the note above this list.
8 samples · Range: 0.0000 to 0.0000 µg/l
Compliance detail is unavailable. This summary alone does not establish that every sample complied.
Original wording and source notes
Source reference: 0.1. Source parameter: Polycyclic aromatic hydrocarbons (sum of 4 PAHs). Original mean: 0.0000 µg/l.
Source note: printed once above this list (the same note appears on 60 parameters).
Pesticides - Total
Mean at or below the source limit
Published mean
0.0010 µg/l
Source reference: 0.5 µg/l
About this parameter: see the note above this list.
34 samples · Range: 0.0000 to 0.0203 µg/l
Compliance detail is unavailable. This summary alone does not establish that every sample complied.
Original wording and source notes
Source reference: 0.5. Source parameter: Pesticides - Total. Original mean: 0.0010 µg/l.
Source note: printed once above this list (the same note appears on 60 parameters).
Taste (quantitative)
Mean at or below the source limit
Published mean
0 dilution number at 25oC
Source reference: 0 dilution number at 25oC
About this parameter: see the note above this list.
47 samples · Range: 0 to 0 dilution number at 25oC
Compliance detail is unavailable. This summary alone does not establish that every sample complied.
Original wording and source notes
Source reference: 0. Source parameter: Taste (quantitative). Original mean: 0 dilution number at 25oC.
Source note: printed once above this list (the same note appears on 60 parameters).
Tetrachloromethane
Reported upper bound at or below the limit
Published mean
<0.504 µg/l
Source reference: 3 µg/l
About this parameter: see the note above this list.
7 samples · Range: <0.380 to <0.670 µg/l
Compliance detail is unavailable. This summary alone does not establish that every sample complied.
“<” is part of the source result. It is not an exact concentration or a measured zero.
Original wording and source notes
Source reference: 3. Source parameter: Tetrachloromethane. Original mean: <0.504 µg/l.
Source note: printed once above this list (the same note appears on 60 parameters).
Trihalomethanes - Total
Mean at or below the source limit
Published mean
31.3 µg/l
Source reference: 100 µg/l
About this parameter: see the note above this list.
7 samples · Range: 25.0 to 44.5 µg/l
Compliance detail is unavailable. This summary alone does not establish that every sample complied.
Original wording and source notes
Source reference: 100. Source parameter: Trihalomethanes - Total. Original mean: 31.3 µg/l.
Source note: printed once above this list (the same note appears on 60 parameters).
Triclopyr
Reported upper bound at or below the limit
Published mean
<0.0170 µg/l
Source reference: 0.1 µg/l
About this parameter: see the note above this list.
25 samples · Range: <0.0170 to <0.0170 µg/l
Compliance detail is unavailable. This summary alone does not establish that every sample complied.
“<” is part of the source result. It is not an exact concentration or a measured zero.
Original wording and source notes
Source reference: 0.1. Source parameter: Triclopyr. Original mean: <0.0170 µg/l.
Source note: printed once above this list (the same note appears on 60 parameters).
Tetrachloroethene and trichloroethene
Mean at or below the source limit
Published mean
0.0000 µg/l
Source reference: 10 µg/l
About this parameter: see the note above this list.
7 samples · Range: 0.0000 to 0.0000 µg/l
Compliance detail is unavailable. This summary alone does not establish that every sample complied.
Original wording and source notes
Source reference: 10. Source parameter: Tetrachloroethene and trichloroethene. Original mean: 0.0000 µg/l.
Source note: printed once above this list (the same note appears on 60 parameters).
Sources, dates and how to interpret this page
- Reporting period
- Rolling 12 months; updated 2026-09-11
- Source retrieved
- 2026-09-13
- Last verified source check
- 2026-09-13
- Original publication
- United Utilities report ↗
Official supplier report for this supply zone, retrieved with postcode PR1 2PP. Town pages that cite this zone show their own supplier-confirmed example postcode. This is an example supply area, not a measurement at every address in the towns it serves.
The supplier describes a rolling 12-month window updated weekly. Its update date is not an exact sampling-period end date. Overlapping rolling windows are not annual trend points.
All published numeric parameters are retained, including censored readings and historical failures. These results are not a statement about current incidents.
Supplier reports 0% of samples failing its requirement. This is a historical percentage, not a current incident or a reconstructed failure count.
Hardness: 34 samples · reported range 42 to 153 mg CaCO3/l.
Status labels describe the published parameter and period. Historical exceedances do not automatically establish a current incident. Numerical limits are taken from the original report, not applied indiscriminately across countries, dates or sampling locations. DWI explains how standards work in England and Wales.
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Questions about water in Preston
Is the water in Preston hard or soft?
Soft. United Utilities’ report for Rolling 12 months; updated 11 September 2026 gives total hardness of 85 mg/l as calcium carbonate for the Preston Central supply area. That is the area returned for the example postcode PR1 2PP; supply can differ by address, so check your full postcode.
Who supplies water in Preston?
United Utilities supplies the example postcode PR1 2PP (Preston Central supply area). Other addresses may differ: check your full postcode or use United Utilities’ water quality information.
Do I need a water softener in Preston?
At 85 mg/l as calcium carbonate, near the top of the soft band (up to 100 mg/l), water leaves little limescale. That is about 4.8 °dH or 6.0 Clark degrees, units many appliance manuals use, so check your dishwasher setting. A softener is not normally needed to reduce scale.
How up to date is the water information for Preston?
Hardness and water-quality results both come from United Utilities’ rolling summary (12 months, updated 11 September 2026). These are area summaries, not live tests of your tap; see the original United Utilities report.