Ensuring Safe Water from Bore and Surface Sources in NZ
If your household water supply comes from a bore, spring, or stream, it’s essential to understand your water chemistry. Water that travels through or over the ground can pick up minerals and contaminants that affect its safety, taste, and treatment effectiveness of your water.
To ensure your water meets the New Zealand Drinking Water Standards (NZDWS), doesn’t damage your plumbing, and can be effectively treated by UV filtration, a laboratory water chemistry test is crucial.
This test, conducted by an accredited lab, identifies whether your water is safe to drink and what treatment (if any) is needed.
If your water tank collects from creeks, dams, or roofs, it’s especially important to stay on top of maintenance. Safe H2O can help with effective cleaning, organised water testing, tailored filtration solutions, and expert advice to keep your surface water fresh, safe, and ready to use.
Common Issues with Bore and Surface Water in NZ
The most frequent water chemistry challenges in New Zealand’s bore and surface water supplies are:
- Hardness
- Iron
- Manganese
Let’s explore each in detail.
Hardness
Water hardness is caused by dissolved minerals, primarily calcium and magnesium, picked up as water moves through soil and rock. It’s measured in mg/L of calcium carbonate (CaCO₃) and classified as:
- Soft: 0–17 mg/L
- Slightly Hard: 17–60 mg/L
- Moderately Hard: 60–120 mg/L
- Hard: 120–180 mg/L
- Very Hard: >180 mg/L
Source: Central Otago District Council
What are the impacts of Hard Water?
- Scale buildup in pipes, appliances, and fixtures
- Reduced soap effectiveness
- Damage to hot water systems
- Interference with UV filtration due to mineral deposits on the quartz sleeve, reducing UV light penetration Iron and Manganese and their Inhibitory Effect on UV performance – Nuvonic
Hard Water Treatment Options
- Water softeners (ion exchange systems)
- Pre-filtration using sediment and carbon filters
Iron and Manganese
These naturally occurring minerals are common in NZ groundwater and can cause:
- Metallic taste
- Staining of laundry, fixtures, and appliances
- Black or orange deposits
- Reduced UV filtration effectiveness due to staining of the UV lamp sleeve Iron and Manganese and their Inhibitory Effect on UV performance – Nuvonic
NZDWS Guidelines:
- Iron: ≤0.3 mg/L (aesthetic guideline)
- Manganese: ≤0.05 mg/L (aesthetic guideline), but UV systems may require levels below these thresholds for effective disinfection
Iron and Manganese Treatment Options:
- Ion exchange systems
- Oxidation and filtration (e.g., air injection, greensand filters)
Nitrates are also a growing issue in New Zealand water supplies – read our blog on nitrates in your water tanks.
Why Water Testing Matters
Only a comprehensive water chemistry test from an IANZ-accredited lab can confirm the presence and concentration of these elements. A list of accredited labs in New Zealand can be found at Laboratories · Hinekōrako
How Safe H2O Can Help
At Safe H2O, we offer a complete solution for water tank owners all over New Zealand.
Tank Cleaning Without Water Loss
Our innovative process cleans your tank and purifies your water using multi-stage filtration and vacuum sediment removal—retaining up to 90% of your water.
Water Testing & Analysis
We can arrange accredited lab testing and provide a custom report outlining your water chemistry, safety status, and treatment recommendations.
Treatment & Filtration Solutions
Based on your test results, we offer quotes for pre-treatment systems (e.g., softeners, iron/manganese filters) and UV filtration units tailored to your water supply and needs.
Ongoing Support
Our team provides advice, maintenance tips, and follow-up services to ensure your water remains safe year-round.
Take Action Today
If your water comes from a bore, spring, or stream, don’t leave your household’s health to chance. Contact Safe H2O for:
- Tank cleaning
- Water testing
- Treatment advice
- Filtration installation
Call us on 0800 723 342 – we’re here to help.