Water Quality Safety Guide for Rental Housing — Risks of Aging Pipes, Legionella Bacteria, and Residual Chlorine, Plus How to Ensure Drinking Water Safety
A guide explaining the risks of water quality degradation from aging pipes and Legionella bacteria. It covers how to verify if your rental home's drinking water is safe, how to request cleaning from your property manager, and how to choose a water purifier.
While tap water safety is often taken for granted, aging rental properties can experience water quality issues due to deteriorating pipes. This article provides a detailed explanation of drinking water risks in rental housing and how to ensure your water is safe.
Water Quality Issues Caused by Aging Pipes
In apartment buildings and residential units built before the 1980s, galvanized steel pipes (white gas pipes) are sometimes used for water supply lines. Over time, these pipes rust internally, and iron and heavy metals can leach into the water.
The main symptoms of rust are red water or brownish-colored water. If reddish water flows from your faucet first thing in the morning or after not using water for a long time, rust inside the pipes is likely the cause. Small amounts often improve by running water for a while, but if it's chronic, the pipes themselves need attention.
In buildings that use storage tanks (water tanks) to distribute water to individual units, the cleanliness of the tank significantly affects water quality. Property managers are required to clean and test storage tanks at least once a year, but if not properly maintained, there is a risk of algae and debris contamination.
Legionella Bacteria Risks
Legionella bacteria are microorganisms that live in water and can cause pneumonia (Legionnaires' disease). In elderly people with weakened immunity or those with underlying health conditions, infection can become severe, and fatal cases have been reported.
Legionella bacteria are most likely to be found in equipment like recirculating bath systems, shower heads, and cooling towers. When mineral deposits and biofilm accumulate inside shower heads, bacteria can flourish. When you move in or after a long period of non-use, it's recommended to remove the shower head, soak and clean it thoroughly, and run the water for a good while before first use.
Shared facilities in rental properties (such as gym showers or public baths) carry particularly high risk. You can confirm whether facilities are properly maintained by checking with your property manager or reviewing resident management reports.
How to Verify Drinking Water Safety
Here are specific steps to verify the safety of your drinking water before or shortly after moving into a rental property.
Visual and odor check: Check the color and smell of water flowing from your faucet first thing in the morning. If it's clear and odorless, there's no problem. Watch out for any yellowish tint, metallic smell, or musty odor.
Commercial water test kits: Available at drugstores and online for around ¥1,000–3,000. They can measure pH, residual chlorine, hardness, lead, iron, and other parameters. The standard residual chlorine level is 0.1 mg/L or higher under water safety regulations; if it's extremely low (below 0.1) or high (2.0 or above), there may be a problem.
Checking water quality information with local authorities: Municipal water departments publish regular water quality test results on their websites. In some cases, you can check data by water distribution zone.
Hiring professional testing agencies: If more detailed testing is needed, you can hire a private water quality testing company. The cost is typically ¥10,000–30,000, and they can perform detailed analysis including lead, arsenic, pesticides, and other contaminants.
Requesting Action from Your Property Manager
If you identify a water quality issue, report it to your property manager or landlord and request action. Maintaining the water supply system in a rental property is the landlord's responsibility, and tenants have the right to request repairs under the Civil Code (Article 606).
When reporting, it's most effective to provide a written notice with specific details about when and where the problem occurs (which faucet, what time of day) and include photos or videos.
You can also request disclosure of storage tank cleaning records and water quality test results. Designated buildings (with floor area of 5,000 m² or larger) are required to conduct periodic inspections under the Building Sanitation Law, and you can access the results.
If the property manager doesn't respond, you can consult with your local health department or a building environmental sanitation management technician (certified building manager).
How to Choose a Water Purifier
If you're concerned about water quality or want to ensure safer drinking water, installing a water purifier is an effective solution.
Faucet-mounted (including under-sink models): The most common type, these remove chlorine, organic compounds, and heavy metals to some degree. Filters need to be replaced regularly (every 6 months to 1 year).
Countertop (pitcher-style): Easy to install and affordable, but has lower processing capacity and requires frequent filter changes.
Reverse osmosis (RO) purifiers: High-performance systems that remove nearly all impurities. They require professional installation and have higher upfront costs (¥100,000–200,000), but compact models suitable for rental properties are available. Check with your property manager before installation.
For rental properties, faucet-mounted or countertop models are the most practical options when considering restoration requirements.
Summary
Water quality issues in rental properties are risks that aren't always visible, but they cannot be ignored, especially in older buildings. When you move in, perform a visual and odor check and a simple water quality test; if problems are found, request action from your property manager. Installing a water purifier to ensure safe drinking water is also an effective way to enjoy a worry-free rental living experience.
