Cornwall vs St Marys

Name: Water Quality Comparison: Cornwall vs St Marys
Creator: WaterScore
License: https://creativecommons.org/licenses/by/4.0/

Side-by-side tap water quality comparison

St Marys, TAS

9.5

Quality Score

Supplied by TasWater

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Which suburb has better water?

It's very close! Cornwall scores 9.5/10 and St Marys scores 9.5/10. Both suburbs have similar water quality based on ADWG compliance data.

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Recommended for this suburb

St Marys's water is hard at 153.333333 mg/L — you're cleaning scale off things that shouldn't need cleaning.

At this level, you'll see white rings inside the kettle, cloudy spots on glassware, and shampoo that never lathers properly. Over 5–10 years, scale slowly kills heating elements in your hot water system and dishwasher — the damage is invisible until they fail 2–3 years early. Boiling doesn't help; it concentrates the minerals.

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Visual comparison

Cornwall, TAS

St Marys, TAS

Key metrics comparison

Hardness (mg/L)

Cornwall

142.857143 Lower

St Marys

153.333333 Higher

pH Level

Cornwall

7.653387 Normal

St Marys

7.10697 Normal

Fluoride (mg/L)

Cornwall

0.943333 Same

St Marys

0.943333 Same

Chlorine (mg/L)

Cornwall

0.787581 Lower

St Marys

0.792576 Higher

Full water quality comparison

All parameters compared against Australian Drinking Water Guidelines (ADWG)

Parameter	Cornwall	St Marys	Unit	ADWG Guideline
Alkalinity	245 Measured	146.666667 Measured	mg/L	No limit
Aluminium	0.01 Good	0.01 Good	mg/L	< 0.2
Ammonia	0.002286 Measured	0.002 Measured	mg/L	No limit
Antimony	0.001 Measured	0.001 Measured	mg/L	No limit
Arsenic	0.001 Measured	0.001 Measured	mg/L	No limit
Cadmium	0.0002 Measured	0.0002 Measured	mg/L	No limit
Calcium	51.166667 Measured	55.5 Measured	mg/L	No limit
Chloride	20 Good	33 Good	mg/L	< 250
Chromium	0.001 Measured	0.001 Measured	mg/L	No limit
Colour	2 Good	2.166667 Good	Pt-Co	< 15
Conductivity	525 Measured	411.666667 Measured	uS/cm	No limit
Copper	0.01125 Good	0.0115 Good	mg/L	< 2
Cyanide	0.005 Measured	0.005 Measured	mg/L	No limit
E. coli	0 Compliant	0 Compliant	MPN/100ml	< 0
Fluoride	0.943333 Good	0.943333 Good	mg/L	< 1.5
Free Chlorine	0.787581 Good	0.792576 Good	mg/L	< 5
Hardness	142.857143 Good	153.333333 Good	mg/L	< 200
Iron	0.01 Good	0.0275 Good	mg/L	< 0.3
Lead	0.001 Good	0.001 Good	mg/L	< 0.01
Magnesium	5.033333 Measured	4.95 Measured	mg/L	No limit
Manganese	0.001 Good	0.00325 Good	mg/L	< 0.1
Mercury	0.0001 Measured	0.0001 Measured	mg/L	No limit
Nickel	0.001 Measured	0.001 Measured	mg/L	No limit
Nitrate	0.041571 Good	0.007333 Good	mg/L	< 50
Nitrite	0.002 Measured	0.002 Measured	mg/L	No limit
pH	7.653387 Normal	7.10697 Normal	pH units	6.5 – 8.5
Sodium	57.833333 Good	17 Good	mg/L	< 180
Sulfate	13.5 Good	14.333333 Good	mg/L	< 500
Temperature	13.970968 Measured	13.442424 Measured	degrees C	No limit
Total Chlorine	0.849286 Good	1 Good	mg/L	< 5
Total Coliforms	0 Compliant	0 Compliant	MPN/100ml	< 0
Total Dissolved Solids	313.333333 Good	231.666667 Good	mg/L	< 600
Trihalomethanes	0.0195 Good	0.0115 Good	mg/L	< 0.25
Turbidity	0.172419 Good	0.57303 Good	NTU	< 5
Zinc	0.004625 Measured	0.0045 Measured	mg/L	No limit

Explore further

Cornwall

St Marys

Disclaimer: This comparison is for general informational purposes only and does not constitute medical advice or professional guidance. Data is sourced from TasWater. Values shown are based on the most recent published water quality reports and may not reflect real-time conditions at your tap. Water quality can vary due to local plumbing, seasonal changes, and other factors. For specific health concerns, consult a qualified health professional or contact your local water utility. See our Terms of Use.