Water hardness and quality in Bull's Green
Page updated · Report periods are shown with each report.
Hertfordshire · Eastern. Explore the published supply-area report and check your postcode for a supplier-confirmed match.
This is a named-area report associated with Bull's Green; it does not confirm the supply at every address.
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
Hard water. Expect limescale.
For your home, the main practical issue is mineral scale in kettles, showers and appliances. Check your dishwasher setting and follow appliance care instructions.
295 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
50 parameters: no exceedances reported
These labels describe 2025. 3 other parameters have no complete compliance judgement here. They are not a guarantee about an individual tap today.
Understand the reported results ↓Make this useful for your home
Hardness reporting period: 2025 · Quality reporting period: 2025
Appliance settings · Convert hardness units
2.95 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.
E. coli
✓ No exceedances reported
Published mean
0 No./100ml
Source reference: 0 No./100ml
A microbiological indicator. The reported sample results and any failures matter more than an average bacterial count.
48 samples · Range: 0 to 0 No./100ml
The source reports 0 failures across 48 samples. This describes the published period.
Lead
✓ No exceedances reported
Published mean
<0.67 μgPb/l
Source reference: 10 μgPb/l
Plumbing can affect lead at an individual tap. An area average cannot rule out a problem with pipes at your property.
8 samples · Range: <0.67 to 0.76 μgPb/l
The source reports 0 failures across 8 samples. This describes the published period.
“<” is part of the source result. It is not an exact concentration or a measured zero.
Nitrate
✓ No exceedances reported
Published mean
26.7 mgNO3/l
Source reference: 50 mgNO3/l
A dissolved compound monitored against drinking-water requirements. Its mean, highest reported result and sample count answer different questions.
24 samples · Range: 21.3 to 31.4 mgNO3/l
The source reports 0 failures across 24 samples. This describes the published period.
Fluoride
✓ No exceedances reported
Published mean
0.225 mgF/l
Source reference: 1.5 mgF/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.
8 samples · Range: 0.181 to 0.253 mgF/l
The source reports 0 failures across 8 samples. This describes the published period.
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 guideManage limescale
Follow the manufacturer’s descaling advice. Check what a filter actually removes before buying.
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.
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 · 55 parameters · 2025
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.
A failure count (under “Original wording and source notes”) supports a pass/fail label only where the report gives an applicable limit for that parameter.
Hardness and minerals 7 parameters
Alkalinity
No numerical limit supplied
Published mean
297 mgHCO3/l
Source reference: No numerical limit supplied
How strongly water resists a change in acidity. This helps describe its chemistry; it is different from pH and total hardness.
48 samples · Range: 244 to 358 mgHCO3/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: No PCV. Source parameter: Alkalinity. Original mean: 297 mgHCO3/l.
Source failure-count field: 0.
Calcium
No numerical limit supplied
Published mean
118 mgCa/l
Source reference: No numerical limit supplied
A naturally occurring mineral that contributes to hardness. Calcium alone is not the same measurement as total hardness.
48 samples · Range: 105 to 140 mgCa/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: No PCV. Source parameter: Calcium. Original mean: 118 mgCa/l.
Source failure-count field: 0.
Fluoride
✓ No exceedances reported
Published mean
0.225 mgF/l
Source reference: 1.5 mgF/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.
8 samples · Range: 0.181 to 0.253 mgF/l
The source reports 0 failures across 8 samples. This describes the published period.
Original wording and source notes
Source reference: 1.5. Source parameter: Fluoride. Original mean: 0.225 mgF/l.
Source failure-count field: 0.
Total hardness
No numerical limit supplied
Published mean
295 mgCaCO3/l
Source reference: No numerical limit supplied
Dissolved calcium and magnesium affect limescale and appliance settings. This is a mineral description, not a safety score.
48 samples · Range: 263 to 350 mgCaCO3/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: No PCV. Source parameter: Hardness (Total). Original mean: 295 mgCaCO3/l.
Source failure-count field: 0.
Sodium
✓ No exceedances reported
Published mean
61.4 mgNa/l
Source reference: 200 mgNa/l
A dissolved salt component. Compare the water measurement with its source reference; it is not a measure of your total dietary salt intake.
8 samples · Range: 31.3 to 101 mgNa/l
The source reports 0 failures across 8 samples. This describes the published period.
Original wording and source notes
Source reference: 200. Source parameter: Sodium. Original mean: 61.4 mgNa/l.
Source failure-count field: 0.
Chloride
✓ No exceedances reported
Published mean
57 mgCl/l
Source reference: 250 mgCl/l
A dissolved salt component that can influence taste at higher concentrations. It is different from chlorine used in treatment.
8 samples · Range: 40 to 77 mgCl/l
The source reports 0 failures across 8 samples. This describes the published period.
Original wording and source notes
Source reference: 250. Source parameter: Chloride. Original mean: 57 mgCl/l.
Source failure-count field: 0.
Sulphate
✓ No exceedances reported
Published mean
96 mgSO4/l
Source reference: 250 mgSO4/l
A dissolved mineral component monitored in water-quality reports. Read its concentration alongside the source reference.
8 samples · Range: 62 to 119 mgSO4/l
The source reports 0 failures across 8 samples. This describes the published period.
Original wording and source notes
Source reference: 250. Source parameter: Sulphate. Original mean: 96 mgSO4/l.
Source failure-count field: 0.
Taste, appearance and treatment 6 parameters
Chlorine residual
No numerical limit supplied
Published mean
0.37 mgCl2/l
Source reference: No numerical limit supplied
Disinfectant remaining after treatment. It can influence taste and smell; a lower concentration is not automatically better.
48 samples · Range: 0.08 to 0.94 mgCl2/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: No PCV. Source parameter: Chlorine (Residual). Original mean: 0.37 mgCl2/l.
Source failure-count field: 0.
Colour
✓ No exceedances reported
Published mean
<2.0 mg/l Pt/Co
Source reference: 20 mg/l Pt/Co
A measure of water colour under test conditions. A new change at your tap should be checked with your supplier.
24 samples · Range: <1.9 to 2.7 mg/l Pt/Co
The source reports 0 failures across 24 samples. This describes the published period.
“<” 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: <2.0 mg/l Pt/Co.
Source failure-count field: 0.
pH
✓ No exceedances reported
Published mean
7.5 pH value
Source reference: 6.5-9.5 pH value
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.
24 samples · Range: 7.1 to 7.9 pH value
The source reports 0 failures across 24 samples. This describes the published period.
Original wording and source notes
Source reference: 6.5-9.5. Source parameter: Hydrogen Ion (pH). Original mean: 7.5 pH value.
Source failure-count field: 0.
Turbidity
✓ No exceedances reported
Published mean
<0.10 NTU
Source reference: 4 NTU
Measures cloudiness caused by suspended particles. It cannot identify their cause on its own.
24 samples · Range: <0.10 to 0.15 NTU
The source reports 0 failures across 24 samples. This describes the published period.
“<” 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: <0.10 NTU.
Source failure-count field: 0.
Conductivity
✓ No exceedances reported
Published mean
698 μS/cm at 20 °C
Source reference: 2500 μS/cm at 20 °C
Indicates how readily water conducts electricity, influenced by dissolved ions. It is not a direct measurement of hardness or safety.
24 samples · Range: 544 to 897 μS/cm at 20 °C
The source reports 0 failures across 24 samples. This describes the published period.
Original wording and source notes
Source reference: 2500. Source parameter: Electrical Conductivity at 20 °C. Original mean: 698 μS/cm at 20 °C.
Source failure-count field: 0.
Total organic carbon
✓ No exceedances reported
Published mean
2.8 mgC/l
Source reference: No abnormal change
A broad measure of organic carbon used to understand water and treatment. It does not identify an individual contaminant.
8 samples · Range: 1.8 to 3.5 mgC/l
The source reports 0 failures across 8 samples. This describes the published period.
Original wording and source notes
Source reference: No abnormal change. Source parameter: Total Organic Carbon. Original mean: 2.8 mgC/l.
Source failure-count field: 0.
Metals 13 parameters
Arsenic
✓ No exceedances reported
Published mean
0.3 μgAs/l
Source reference: 10 μgAs/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: 0.3 to 0.4 μgAs/l
The source reports 0 failures across 8 samples. This describes the published period.
Original wording and source notes
Source reference: 10. Source parameter: Arsenic. Original mean: 0.3 μgAs/l.
Source failure-count field: 0.
Aluminium
✓ No exceedances reported
Published mean
<2.0 μgAl/l
Source reference: 200 μgAl/l
Monitored as part of water-quality testing and treatment control. Compare with the reference and sample results in the source.
24 samples · Range: <2.0 to 2.6 μgAl/l
The source reports 0 failures across 24 samples. This describes the published period.
“<” 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: <2.0 μgAl/l.
Source failure-count field: 0.
Antimony
✓ No exceedances reported
Published mean
0.29 μgSb/l
Source reference: 5 μgSb/l
A trace element monitored in drinking water. The source reference and sample results provide the relevant comparison.
8 samples · Range: 0.16 to 0.46 μgSb/l
The source reports 0 failures across 8 samples. This describes the published period.
Original wording and source notes
Source reference: 5. Source parameter: Antimony. Original mean: 0.29 μgSb/l.
Source failure-count field: 0.
Cadmium
✓ No exceedances reported
Published mean
<0.05 μgCd/l
Source reference: 5 μgCd/l
A trace metal monitored in drinking water. A less-than result reports an upper bound, not a measured zero.
8 samples · Range: <0.05 to <0.05 μgCd/l
The source reports 0 failures across 8 samples. This describes the published period.
“<” 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: <0.05 μgCd/l.
Source failure-count field: 0.
Chromium
✓ No exceedances reported
Published mean
<0.4 μgCr/l
Source reference: 50 μgCr/l
A trace metal monitored in drinking-water reports. Keep the source’s chemical definition and units when comparing results.
8 samples · Range: <0.4 to 0.6 μgCr/l
The source reports 0 failures across 8 samples. This describes the published period.
“<” 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: <0.4 μgCr/l.
Source failure-count field: 0.
Copper
✓ No exceedances reported
Published mean
0.022 mgCu/l
Source reference: 2 mgCu/l
Can be influenced by plumbing. The area report does not replace investigation of a problem at an individual property.
7 samples · Range: <0.003 to 0.121 mgCu/l
The source reports 0 failures across 7 samples. This describes the published period.
Original wording and source notes
Source reference: 2. Source parameter: Copper. Original mean: 0.022 mgCu/l.
Source failure-count field: 0.
Iron
✓ No exceedances reported
Published mean
<9.0 μgFe/l
Source reference: 200 μgFe/l
Can affect water colour, staining and taste. A historical result does not diagnose a change in your tap water today.
24 samples · Range: <3.3 to <9.0 μgFe/l
The source reports 0 failures across 24 samples. This describes the published period.
“<” 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: <9.0 μgFe/l.
Source failure-count field: 0.
Lead
✓ No exceedances reported
Published mean
<0.67 μgPb/l
Source reference: 10 μgPb/l
Plumbing can affect lead at an individual tap. An area average cannot rule out a problem with pipes at your property.
8 samples · Range: <0.67 to 0.76 μgPb/l
The source reports 0 failures across 8 samples. This describes the published period.
“<” 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: <0.67 μgPb/l.
Source failure-count field: 0.
Manganese
✓ No exceedances reported
Published mean
<0.4 μgMn/l
Source reference: 50 μgMn/l
Can affect colour and deposits. Any reported exceedance needs the supplier’s investigation context.
24 samples · Range: <0.4 to 0.4 μgMn/l
The source reports 0 failures across 24 samples. This describes the published period.
“<” 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: <0.4 μgMn/l.
Source failure-count field: 0.
Mercury
✓ No exceedances reported
Published mean
<0.02 μgHg/l
Source reference: 1 μgHg/l
A trace metal monitored against drinking-water requirements. Keep detection limits separate from exact measurements.
8 samples · Range: <0.02 to <0.02 μgHg/l
The source reports 0 failures across 8 samples. This describes the published period.
“<” 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: <0.02 μgHg/l.
Source failure-count field: 0.
Nickel
✓ No exceedances reported
Published mean
2.3 μgNi/l
Source reference: 20 μgNi/l
A monitored metal that can be influenced by materials in contact with water. Local plumbing and sampling context matter.
8 samples · Range: 1.3 to 3 μgNi/l
The source reports 0 failures across 8 samples. This describes the published period.
Original wording and source notes
Source reference: 20. Source parameter: Nickel. Original mean: 2.3 μgNi/l.
Source failure-count field: 0.
Boron
✓ No exceedances reported
Published mean
0.068 mgB/l
Source reference: 1 mgB/l
A dissolved element monitored in drinking water. The source reference applies to the parameter and units shown here.
8 samples · Range: <0.045 to 0.097 mgB/l
The source reports 0 failures across 8 samples. This describes the published period.
Original wording and source notes
Source reference: 1. Source parameter: Boron. Original mean: 0.068 mgB/l.
Source failure-count field: 0.
Selenium
✓ No exceedances reported
Published mean
<0.4 μgSe/l
Source reference: 10 μgSe/l
A trace element monitored in drinking water. Its presence alone does not establish that a requirement was exceeded.
8 samples · Range: <0.4 to <0.4 μgSe/l
The source reports 0 failures across 8 samples. This describes the published period.
“<” 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: <0.4 μgSe/l.
Source failure-count field: 0.
Microbiology 5 parameters
Coliform bacteria
✓ No exceedances reported
Published mean
0 No./100ml
Source reference: 0 No./100ml
Used to monitor water-system hygiene. Interpret detections with the supplier’s sampling location and investigation notes.
48 samples · Range: 0 to 0 No./100ml
The source reports 0 failures across 48 samples. This describes the published period.
Original wording and source notes
Source reference: 0. Source parameter: Coliform bacteria. Original mean: 0 No./100ml.
Source failure-count field: 0.
E. coli
✓ No exceedances reported
Published mean
0 No./100ml
Source reference: 0 No./100ml
A microbiological indicator. The reported sample results and any failures matter more than an average bacterial count.
48 samples · Range: 0 to 0 No./100ml
The source reports 0 failures across 48 samples. This describes the published period.
Original wording and source notes
Source reference: 0. Source parameter: E coli. Original mean: 0 No./100ml.
Source failure-count field: 0.
Clostridium perfringens
✓ No exceedances reported
Published mean
0 No./100ml
Source reference: 0 No./100ml
A microbiological indicator used in water-quality monitoring. Check the sample results and source investigation context.
24 samples · Range: 0 to 0 No./100ml
The source reports 0 failures across 24 samples. This describes the published period.
Original wording and source notes
Source reference: 0. Source parameter: Clostridium perfringens. Original mean: 0 No./100ml.
Source failure-count field: 0.
Enterococci
✓ No exceedances reported
Published mean
0 No./100ml
Source reference: 0 No./100ml
A microbiological indicator assessed through sample results. Read any reported failures with the supplier’s investigation notes.
8 samples · Range: 0 to 0 No./100ml
The source reports 0 failures across 8 samples. This describes the published period.
Original wording and source notes
Source reference: 0. Source parameter: Enterococci. Original mean: 0 No./100ml.
Source failure-count field: 0.
Colony count at 22°C
✓ No exceedances reported
Published mean
2 No./1ml at 22 °C
Source reference: No abnormal change
A general bacterial count used to monitor changes in the supply. It is not equivalent to an E. coli result.
24 samples · Range: 0 to 35 No./1ml at 22 °C
The source reports 0 failures across 24 samples. This describes the published period.
Original wording and source notes
Source reference: No abnormal change. Source parameter: 3 day plate count 22 °C. Original mean: 2 No./1ml at 22 °C.
Source failure-count field: 0.
Other monitored substances 24 parameters
Temperature
No numerical limit supplied
Published mean
14.7 °C
Source reference: No numerical limit supplied
About this parameter: see the note above this list.
48 samples · Range: 6.8 to 22.2 °C
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: No PCV. Source parameter: Temperature. Original mean: 14.7 °C.
Source failure-count field: 0.
Atrazine
✓ No exceedances reported
Published mean
<0.011 μg/l
Source reference: 0.1 μg/l
About this parameter: see the note above this list.
8 samples · Range: <0.011 to <0.011 μg/l
The source reports 0 failures across 8 samples. This describes the published period.
“<” 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: Atrazine. Original mean: <0.011 μg/l.
Source failure-count field: 0.
Carbetamide
✓ No exceedances reported
Published mean
<0.007 μg/l
Source reference: 0.1 μg/l
About this parameter: see the note above this list.
8 samples · Range: <0.007 to <0.007 μg/l
The source reports 0 failures across 8 samples. This describes the published period.
“<” 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: Carbetamide. Original mean: <0.007 μg/l.
Source failure-count field: 0.
Clopyralid
✓ No exceedances reported
Published mean
<0.019 μg/l
Source reference: 0.1 μg/l
About this parameter: see the note above this list.
8 samples · Range: <0.019 to 0.024 μg/l
The source reports 0 failures across 8 samples. This describes the published period.
“<” 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: <0.019 μg/l.
Source failure-count field: 0.
Glyphosate
✓ No exceedances reported
Published mean
<0.005 μg/l
Source reference: 0.1 μg/l
About this parameter: see the note above this list.
8 samples · Range: <0.005 to <0.005 μg/l
The source reports 0 failures across 8 samples. This describes the published period.
“<” 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: <0.005 μg/l.
Source failure-count field: 0.
Mecoprop
✓ No exceedances reported
Published mean
<0.006 μg/l
Source reference: 0.1 μg/l
About this parameter: see the note above this list.
8 samples · Range: <0.006 to <0.006 μg/l
The source reports 0 failures across 8 samples. This describes the published period.
“<” 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: <0.006 μg/l.
Source failure-count field: 0.
Metaldehyde
✓ No exceedances reported
Published mean
<0.009 μg/l
Source reference: 0.1 μg/l
About this parameter: see the note above this list.
8 samples · Range: <0.009 to 0.011 μg/l
The source reports 0 failures across 8 samples. This describes the published period.
“<” 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: Metaldehyde. Original mean: <0.009 μg/l.
Source failure-count field: 0.
Metazachlor
✓ No exceedances reported
Published mean
<0.008 μg/l
Source reference: 0.1 μg/l
About this parameter: see the note above this list.
8 samples · Range: <0.008 to <0.008 μg/l
The source reports 0 failures across 8 samples. This describes the published period.
“<” 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: Metazachlor. Original mean: <0.008 μg/l.
Source failure-count field: 0.
Propyzamide
✓ No exceedances reported
Published mean
0.014 μg/l
Source reference: 0.1 μg/l
About this parameter: see the note above this list.
8 samples · Range: 0.009 to 0.018 μg/l
The source reports 0 failures across 8 samples. This describes the published period.
Original wording and source notes
Source reference: 0.1. Source parameter: Propyzamide. Original mean: 0.014 μg/l.
Source failure-count field: 0.
Simazine
✓ No exceedances reported
Published mean
<0.009 μg/l
Source reference: 0.1 μg/l
About this parameter: see the note above this list.
8 samples · Range: <0.009 to <0.009 μg/l
The source reports 0 failures across 8 samples. This describes the published period.
“<” 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: Simazine. Original mean: <0.009 μg/l.
Source failure-count field: 0.
2,4-D
✓ No exceedances reported
Published mean
<0.008 μg/l
Source reference: 0.1 μg/l
About this parameter: see the note above this list.
8 samples · Range: <0.008 to <0.008 μg/l
The source reports 0 failures across 8 samples. This describes the published period.
“<” 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: <0.008 μg/l.
Source failure-count field: 0.
Total Pesticide
✓ No exceedances reported
Published mean
0.027 μg/l
Source reference: 0.5 μg/l
About this parameter: see the note above this list.
8 samples · Range: 0.014 to 0.044 μg/l
The source reports 0 failures across 8 samples. This describes the published period.
Original wording and source notes
Source reference: 0.5. Source parameter: Total Pesticide. Original mean: 0.027 μg/l.
Source failure-count field: 0.
Ammonium
✓ No exceedances reported
Published mean
<0.06 mgNH4/l
Source reference: 0.5 mgNH4/l
About this parameter: see the note above this list.
24 samples · Range: <0.05 to 0.16 mgNH4/l
The source reports 0 failures across 24 samples. This describes the published period.
“<” 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. Original mean: <0.06 mgNH4/l.
Source failure-count field: 0.
Benzene
✓ No exceedances reported
Published mean
<0.18 μg/l
Source reference: 1 μg/l
About this parameter: see the note above this list.
8 samples · Range: <0.17 to <0.18 μg/l
The source reports 0 failures across 8 samples. This describes the published period.
“<” 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: <0.18 μg/l.
Source failure-count field: 0.
Benzo (a) Pyrene
✓ No exceedances reported
Published mean
<0.001 μg/l
Source reference: 0.01 μg/l
About this parameter: see the note above this list.
8 samples · Range: <0.001 to <0.001 μg/l
The source reports 0 failures across 8 samples. This describes the published period.
“<” 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: <0.001 μg/l.
Source failure-count field: 0.
Bromate
✓ No exceedances reported
Published mean
<1.5 μgBrO3/l
Source reference: 10 μgBrO3/l
About this parameter: see the note above this list.
8 samples · Range: <1.5 to 2.1 μgBrO3/l
The source reports 0 failures across 8 samples. This describes the published period.
“<” 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: <1.5 μgBrO3/l.
Source failure-count field: 0.
Nitrate
✓ No exceedances reported
Published mean
26.7 mgNO3/l
Source reference: 50 mgNO3/l
A dissolved compound monitored against drinking-water requirements. Its mean, highest reported result and sample count answer different questions.
24 samples · Range: 21.3 to 31.4 mgNO3/l
The source reports 0 failures across 24 samples. This describes the published period.
Original wording and source notes
Source reference: 50. Source parameter: Nitrate. Original mean: 26.7 mgNO3/l.
Source failure-count field: 0.
Nitrite
✓ No exceedances reported
Published mean
<0.010 mgNO2/l
Source reference: 0.5 mgNO2/l
A nitrogen compound monitored in water supplies. Requirements can depend on where the sample was collected; use the reference printed in this report.
24 samples · Range: <0.007 to 0.012 mgNO2/l
The source reports 0 failures across 24 samples. This describes the published period.
“<” 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: <0.010 mgNO2/l.
Source failure-count field: 0.
Sum of Tri & Tetrachloroethene
✓ No exceedances reported
Published mean
0 μg/l
Source reference: 10 μg/l
About this parameter: see the note above this list.
9 samples · Range: 0 to 0 μg/l
The source reports 0 failures across 9 samples. This describes the published period.
Original wording and source notes
Source reference: 10. Source parameter: Sum of Tri & Tetrachloroethene. Original mean: 0 μg/l.
Source failure-count field: 0.
Tetrachloromethane
✓ No exceedances reported
Published mean
<0.2 μg/l
Source reference: 3 μg/l
About this parameter: see the note above this list.
9 samples · Range: <0.2 to <0.2 μg/l
The source reports 0 failures across 9 samples. This describes the published period.
“<” 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: <0.2 μg/l.
Source failure-count field: 0.
Total Cyanide
✓ No exceedances reported
Published mean
<6.5 μgCN/l
Source reference: 50 μgCN/l
About this parameter: see the note above this list.
8 samples · Range: <6.5 to <6.5 μgCN/l
The source reports 0 failures across 8 samples. This describes the published period.
“<” 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: Total Cyanide. Original mean: <6.5 μgCN/l.
Source failure-count field: 0.
Total PAHs
✓ No exceedances reported
Published mean
0 μg/l
Source reference: 0.1 μg/l
About this parameter: see the note above this list.
9 samples · Range: 0 to 0 μg/l
The source reports 0 failures across 9 samples. This describes the published period.
Original wording and source notes
Source reference: 0.1. Source parameter: Total PAHs. Original mean: 0 μg/l.
Source failure-count field: 0.
Total Trihalomethanes
✓ No exceedances reported
Published mean
29.59 μg/l
Source reference: 100 μg/l
About this parameter: see the note above this list.
9 samples · Range: 16.26 to 46.35 μg/l
The source reports 0 failures across 9 samples. This describes the published period.
Original wording and source notes
Source reference: 100. Source parameter: Total Trihalomethanes. Original mean: 29.59 μg/l.
Source failure-count field: 0.
1, 2 dichloroethane
✓ No exceedances reported
Published mean
<0.15 μg/l
Source reference: 3 μg/l
About this parameter: see the note above this list.
9 samples · Range: <0.15 to <0.15 μg/l
The source reports 0 failures across 9 samples. This describes the published period.
“<” 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: <0.15 μg/l.
Source failure-count field: 0.
Sources, dates and how to interpret this page
- Reporting period
- 2025
- Source retrieved
- 2026-02-26
- Last verified source check
- 2026-09-13
- Original publication
- Affinity Water report ↗
Published area statistics are not a test at your home or a current incident report.
Hardness: 48 samples · reported range 263 to 350 mgCaCO3/l.
Affinity’s live hardness summary can differ from its annual report. Check the reporting periods before treating a difference as a trend.
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 Bull's Green
Is the water in Bull's Green hard or soft?
Hard. Affinity Water’s 2025 report gives total hardness of 295 mg/l as calcium carbonate for the Knebworth/Tewin supply area. This is a named-area report, not confirmation of the supply at every address, so check your full postcode.
Who supplies water in Bull's Green?
Affinity Water publishes the report for the Knebworth/Tewin supply area shown on this page, an area associated with Bull's Green. Other addresses may differ: check your full postcode or use Affinity Water’s water quality information.
Do I need a water softener in Bull's Green?
At 295 mg/l as calcium carbonate, near the top of the hard band (above 200 to 300 mg/l), limescale in kettles, showers and appliances is the main household issue. That is about 16.5 °dH or 20.7 Clark degrees, units many appliance manuals use, so check your dishwasher setting. A softener is a household choice, not a requirement; check what a filter or softener actually does before buying.
How up to date is the water information for Bull's Green?
Hardness and water-quality results both come from Affinity Water’s 2025 annual report. These are area summaries, not live tests of your tap; see the original Affinity Water report.