Heavy Metals in Drinking Water: 5 Sources and 5 Solutions

January 14, 2025

Contents

Where heavy metals come from Standards and points to note for heavy metals in drinking water Ways to reduce heavy metal exposure Summary Frequently asked questions Related Further Reading

By: Bio-Link Technical Team

Heavy metals are a class of denser metallic elements — lead, mercury, cadmium, arsenic, chromium and nickel among them. They occur widely in the natural environment and can enter drinking water systems by several routes. As attention to drinking water quality grows, understanding the common sources of heavy metals and the ways water quality is managed helps you make better-grounded decisions. This article looks at five sources of heavy metals in drinking water and five ways to respond.

Where heavy metals come from

The main sources of heavy metal contamination include:

Industrial discharge: many industrial processes release heavy metals — smelting, electroplating and chemical manufacturing among them.
Pesticides and fertilisers: some contain heavy metals, which can reach water sources through surface runoff.
Urban sewage: poorly treated sewage can carry heavy metals into drinking water systems.
Ageing pipework: even where the treatment works supplies water that meets standards, the internal pipework of older buildings can be a source of concern. Some older pipe materials age with long service, which can affect the colour, smell or taste of water at the tap. If you live in an older building, look into the state of its pipework and consider arranging a water test.
Natural sources: in some areas heavy metals occur naturally in soil and rock, and can be carried into groundwater by rainfall.

Standards and points to note for heavy metals in drinking water

Drinking water safety standards in most jurisdictions — including the World Health Organization guidelines that Hong Kong's Water Supplies Department follows — set limits for lead, mercury, cadmium, arsenic and other heavy metals, to control the potential long-term health effects of drinking water. Where supply meets the standards, the everyday risk is very low.

The following situations may deserve attention, though:

Internal pipes in older buildings: some older buildings (especially pre-1980s construction) may use older pipe materials; where pipes have aged or maintenance has lapsed, water at the tap can be affected.
Under-cleaned tanks: rooftop or basement storage tanks that are not cleaned regularly can accumulate sediment, affecting how the water looks.
Groundwater near industrial or agricultural areas: in some areas, geology or surroundings can leave groundwater or natural sources higher in heavy metals — have the water tested before use.

If you have doubts about your water, consult the Hong Kong Water Supplies Department first (hotline: 2824 5000) or arrange an independent water test, and decide whether filtration equipment is needed once you know the facts. For specific health questions, consult a qualified medical professional.

Ways to reduce heavy metal exposure

Water testing: test your household drinking water regularly to confirm it is free of harmful heavy metals.
Install a reverse osmosis (RO) filtration system: an RO system uses a semi-permeable membrane and helps reduce dissolved solids and some metal ions — one of the common point-of-use choices in Hong Kong and Macau homes. Actual results vary with the system specification, cartridge condition and maintenance schedule. Further reading: What Is RO Water? The Complete Reverse Osmosis Guide
Know your water source: mains supply in Hong Kong and Macau is regulated and generally meets drinking water standards. If you have doubts about the source, contact the Water Supplies Department or your property management office, or request a free on-site assessment.
Keep good habits: avoid products that may contain heavy metals, such as certain cosmetics or cleaning agents.
Renew old pipework: if you live in an older building, have ageing supply pipes inspected and replaced to reduce the risk of heavy metals leaching into drinking water.

Summary

Knowing the common sources of heavy metals in drinking water helps you manage everyday water quality on firmer ground. Mains supply in Hong Kong and Macau is regulated and everyday risk is very low, but the state of pipework inside buildings varies with age and upkeep, and deserves regular attention.

Regular water testing, knowing the state of your pipes, and choosing filtration to match actual needs are the practical steps of everyday water management. For more on how RO systems work and how to choose one, see:

Frequently asked questions

How do I know whether my drinking water contains heavy metals?

Heavy metal levels in drinking water usually cannot be judged from how the water looks or smells. If in doubt, start by finding out when your building's pipework was built and what it is made of, and arrange a water test for real data. Hong Kong residents can request the Water Supplies Department's free on-site water testing service (hotline: 2824 5000); Macau residents can contact Macao Water about arrangements. With data in hand it is far easier to judge whether filtration is needed and which configuration fits.

Do Hong Kong and Macau set standards for heavy metals in supply?

Yes. The Water Supplies Department's drinking water standards follow the WHO Guidelines for Drinking-water Quality, with limits for lead, cadmium, arsenic, mercury and other metals. Macau's water authority runs a corresponding monitoring regime. Water leaving the works within standards normally carries very low risk in ordinary use, but the condition of ageing pipes inside buildings varies with each building's age and maintenance record, and can affect how water looks and what it carries by the time it reaches the tap. For specifics, see the official information from the Water Supplies Department or Macau's water authority.

Does a home RO system help with metal ions in water?

An RO reverse osmosis system uses a semi-permeable membrane and helps reduce dissolved solids and some metal ions — a common choice for everyday home water management. Actual results vary with the system specification, cartridge model and maintenance schedule. When buying, understand the technical specification and the recommended cartridge replacement cycle so the system keeps working effectively. If needed, test the water first and choose the filtration solution by the results.

Who should I contact if I suspect a water-quality problem at home?

Hong Kong residents can call the Water Supplies Department (2824 5000) or request its free on-site water testing; Macau residents can contact the Macao Water Supply Company. For problems with a building's communal supply or rooftop tanks, raise it with the property management office or owners' corporation and ask for inspection or cleaning. For specific health questions, consult a qualified medical professional rather than relying on drinking arrangements alone. If a home filtration solution is confirmed, contact Bio-Link about RO838 or DT400 and arrange an installation assessment.

Interested in a home-friendly Water Purifier or Water Dispenser options for the home? Compare Bio-Link's current home solutions by installation space and daily needs:

RO838: an under-sink RO filter with multi-stage filtration, suited to kitchen installation for daily drinking and cooking.
DT400: tabletop instant-hot water dispenser; filtration options can be added depending on installation conditions. Suitable for kitchens or living rooms.

Want to see suitable Office Water Dispenser options? Compare Bio-Link's current commercial solutions by headcount, space and maintenance arrangements:

ST1523: suited to medium and large offices, with higher capacity and RO filtration for shared pantries.
ST9102: suited to schools, educational institutions and heavily shared venues — durable design with fixed maintenance arrangements.
STC15: suited to small offices, clinics or studios with limited space, supporting compact commercial installations.

Why choose Bio-Link?

Bio-Link (霸力純水濾水系統) is one of Hong Kong and Macau's longest-established reverse-osmosis (RO) drinking-water specialists, operating since 1997 — nearly three decades focused almost entirely on RO. We supply, install and maintain direct-piped RO and UF drinking-water systems for homes, offices, schools, clinics, restaurants and hotels across Hong Kong and Macau, with one company handling supply, installation and maintenance end to end, to buy or to rent, with clear costs. Our full filtration line is SGS-tested and designated models meet NSF 42 & 58; Bio-Link is a certified Social Enterprise (HKCSS / SEE Mark SEE0195). Bio-Link is a reliable choice for office water dispensers for companies large and small.

Further Reading:Reverse osmosis - Wikipedia