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Water quality

Final update date May 8, 2020

Water quality

QQ
1.The water is colored, foreign matter comes out.
A.

If the water is white, pour it into a transparent container and leave it for a while. If there is no sediment and it becomes transparent from below, it is considered that the air in the tap water became fine bubbles and the water looked white. In this case, you can drink it. If there is a sinking object and it does not become transparent, stop drinking and call Water Works Bureau Customer Service Center. I'll visit the water test.
Red water may come out when iron pipes (zinc steel pipes) are used. If you flush a bucket and become transparent, you can drink it. If you are worried, we will visit you for a water test.
If black or blue water comes out, stop drinking and contact us. The same applies to foreign matter. The Water Works Bureau's water quality inspection is free of charge

[Example 1 of common foreign matter]
Features

Black and easy to float, fragments and granular foreign matter

An enlarged photo of a black foreign object

Cause

It is considered that the black rubber packing used around the faucet has deteriorated.
The main ingredient is ethylene-propylene-diene rubber (EPDM), and there is no harm to the body even if swallowed by mistake.

Measures

As a provisional measure, there is a method of attaching a filter etc. to the faucet.
As a fundamental solution, it is necessary to replace the packing.


[Example 2 of common foreign matter]
Features

Brown, easy to sink, fragments and granular foreign matter

An enlarged photo of a brown foreign object

Cause

It is considered to be iron rust generated by the deterioration of water pipes (water pipes, water pipes).
Iron is a necessary ingredient for the human body, and there is no harm to the body even if swallowed by mistake.

Measures

As a provisional measure, there is a method of attaching a filter etc. to the faucet.
The fundamental solution is to replace and clean water pipes.


[Example 3 of common foreign matter]
Features

Yellow-green, green-white foreign body

An enlarged photo of a yellow-green string-shaped foreign object

Extended photo of green white debris

Deterioration of inner hose


Cause

It is considered that the inner hose of the shower head type hydrant etc. has deteriorated.
There are fragments, membranes, strings, etc.
The main ingredient is polyethylene and polypropylene, and there is no harm to the body even if swallowed by mistake.

Measures

As a provisional measure, there is a method of attaching a filter etc. to the faucet.
As a fundamental solution, it is necessary to replace the hose.

QQ
2.Is tap water safe?
A.

Tap water has a tap water quality standard that fully considers safety by the government, and water utilities across the country are obliged to comply and inspect it.
According to Article 4 of the Water Supply Law, tap water quality standards have six requirements, such as not being contaminated with pathogenic organisms and not containing toxic substances. As a specific standard, a ministerial ordinance on water quality standards sets 51 standard values.
Yokohama City supplies customers with "safe and high-quality water" by independently setting "water quality management values" that are stricter than national standards and properly water quality management from water sources to faucets. .

QQ
3.I'm worried about the water quality of the water supply. Can you do a water test?
A.

In Water Works Bureau City goes to the customer's home where you would like to have a water test and conducts a free water test at the faucet.
To apply, please contact Water Works Bureau, please.
In addition, in large-scale condominiums and buildings, if the effective capacity of the receiving tank exceeds 100 cubic meters (except some), a technical manager is assigned and regular cleaning is performed. Not subject to water quality inspection.

QQ
4.Was asbestos cement pipe (asbestos pipe) used for water pipe?
A.

Asbestos cement pipes (asbestos pipes) have been used in Japan since the early Showa era because they are cheap and easy to process.
However, asbestos-cement pipes have deteriorated quickly and have been a major cause of water leakage, so asbestos-cement pipes have not been used for water pipes in Yokohama City since 1968.
The Ministry of Health, Labor and Welfare has set water quality standards because asbestos has a smaller toxicity associated with ingestion than inhalation from the respiratory tract, and the amount of asbestos in tap water is not at a problematic level. I do not go.
The World Health Organization (WHO) Guidelines for Drinking Water Quality also states that asbestos in drinking water does not need to set guidelines from the viewpoint of health effects.

QQ
5.About lead water pipe
A.

If a lead water pipe is used for your home water pipe, a small amount of lead may be dissolved in the accumulated tap water. Use the first water in the morning for anything other than drinking. There is no health problem for drinking after running water.

QQ
6.I live in apartment lives. Is it OK to manage the sanitation of water tanks?
A.

Health and Social Welfare Bureau was responsible for the management and water quality of water supply facilities from receiving tanks to faucets in condominiums and buildings. However, due to hygiene problems caused by inadequate management, a water supply law was revised in June 2001, and even in Water Works Bureau because of hygiene problems caused by inadequate management.
Yokohama City revised the Water Supply Ordinance in December 2002 and has taken the following measures.
(1) In response to a request from a water tank water user (resident), Water Works Bureau request from user (resident) of water tank water supply and informs the result.
(2) As a result of water quality inspections at faucets, if there is a problem with water quality safety, it is recognized that it is necessary to jointly conduct water quality inspections and inspections in water receiving tanks in cooperation with Health and Social Welfare Bureau water tank installer. Water quality inspections are not included in the Water Supply Law Enforcement Regulations.
(i) Users' interest in water quality is high.
(iii) Equalize services with users of detached houses.
(iiii) In consideration of the necessity of water quality inspection to judge the management situation of water tank water supply, we made the regulations as Motoichi original correspondence.
In addition, contents of management responsibility of water tank water supply installer based on regulations ("the regulations about securing of safe, hygienic drinking water in Yokohama-shi simple water supply and small-scale receiving tank water supply") of Water Supply Law and Health and Social Welfare Bureau jurisdiction There is no change.

For inquiries about water supply, please contact Water Works Bureau Customer Service Center.

Water Works Bureau Customer Service Center

Telephone: 045-847-6262 Fax: 045-848-4281
※Please be careful not to make a mistake.

Inquiries to this page

Water Works Bureau Water Purification Department Water Quality Division

Telephone: 045-37-5656

Telephone: 045-37-5656

Fax: 045-37-6942

Email address: [email protected]

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