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The quality of the water

Last update date May 8, 2020

About the quality of the water

Q
1.It is colored in water, and alien substance exits
A

When water is white, you flow into transparent container, and please leave unattended for a while. There is not the sediment, and air in tap water becomes small air bubbles from bottom when it becomes transparent, and it is thought that water was seen white. In this case it shines for drinking and supports, and there are none. There is the sediment and stops drinking when you do not become transparent, and please call Water Works Bureau customer Service Center. We hear from examination of water.
When red water uses iron pipe (zinc steel tube), we may appear. It carries away around one cup of bucket and shines for drinking if it becomes transparent and supports, and there are none. If it is worry, we ask examination of water.
When black and blue water flow, you stop drinking, and please contact. When alien substance appears, it is similar. Examination of water by Water Works Bureau is free.

[example 1 of common alien substance]
Characteristic

Is easy to float with black, piece form and granular alien substance

Macrophotograph of black alien substance

Cause

It is thought that black rubber packing used for faucet rotations deteriorated.
Chief ingredient is ethylene - propylene - diene rubber (EPDM), and body does not have harm even if we swallow by mistake.

Measures

Temporary measures include method to attach filters to faucet.
For basic solution, exchange of packing is necessary.


[example 2 of common alien substance]
Characteristic

Is easy to be depressed by brown, piece form and granular alien substance

Macrophotograph of brown alien substance

Cause

It is thought that it is iron rust which water pipe (service pipe, water pipe) deteriorates, and was generated.
It is necessary ingredient, and, as for iron, body does not have harm for the human body even if we swallow by mistake.

Measures

Temporary measures include method to attach filters to faucet.
Basic solution includes methods such as exchange, cleaning of water pipe.


[example 3 of common alien substance]
Characteristic

Alien substance of yellow green, green white

Macrophotograph of yellowish green string-formed alien substance

Macrophotograph of green white piece-formed alien substance

Photograph of inner hose inside deterioration


Cause

It is thought that it is deterioration of the inner hose inside such as shower head type feed cocks.
Piece form is filmy, and there are string-shape things.
Chief ingredient is polyethylene and polypropylene, and body does not have harm even if we swallow by mistake.

Measures

Temporary measures include method to attach filters to faucet.
For basic solution, exchange of hose is necessary.

Q
2.Is tap water safe?
A

Water supply standard of water which considered safety enough is set of tap water by country, and the observance and inspection are required in water supply companies of the whole country.
We include six requirements such as standard of water of tap water not being polluted to the cause of the disease living thing by water supply method Article 4 or not including toxic substance. As this concrete standard, the standard value of 51 items is set in the departmental order about standard of water.
In Yokohama-shi, we set "water quality management value" that is severer than standard of country originally and by performing water quality management from water source to faucet appropriately, supply "water high quality by security" to customer.

Q
3.You are worried about quality of tap water, will you examine water?
A

In Water Works Bureau, we go to home of customer that examination of water is hoped for and perform examination of water with faucet free.
We would like application to Water Works Bureau customer Service Center.
In addition, we are out of this examination of water because technique manager is located in (excluded partly) when effective capacity of cistern to receive in large-scale apartment buildings exceeds 100 cubic meters, and periodical cleaning is done.

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

Because asbestos-cement pipe (asbestos pipe) was easy to process price cheaply, it was used in the country from the early days of the Showa era.
However, asbestos-cement pipe is not used for water pipe of Yokohama-shi now because we pushed forward exchange sequentially from 1968 as aged deterioration is early, and asbestos-cement pipe became big cause of leaking water.
In addition, in Ministry of Health, Labour and Welfare, asbestos is full of the toxicity accompanied with ingestion in comparison with inhalation from respiratory organs, and, also, abundance of asbestos in tap water does not set standard of water in problem and level that it is small because there is not.
In the guidelines for drinking-water quality of the World Health Organization (WHO), it is said, "we can conclude that it is not necessary to set guidelines level from the viewpoint of healthy influence" about asbestos in drinking water.

Q
5.About service pipe made of lead
A

When service pipe made of lead is used for service pipe of home, a very small amount of lead may dissolve in tap water which stayed. Please use first thing in the morning water other than drinking. About the later running water, there is no health problem even if we drink.

Q
6.They live in apartment, is hygiene management such as water tanks all right?
A

About management and the quality of the water about waterworks from cistern to receive in apartment buildings to faucet, it was jurisdiction of Health and Social Welfare Bureau. However, because sanitary problem by incompleteness of management occurs, the water supply method is revised in June, 2001, and even Water Works Bureau supplying water to will participate about management of water tank Channel.
In Yokohama-shi, it revises the water supply regulations in December, 2002 and gives following response.
(1) Depending on request from user (inhabitants) for water tank water supply, Water Works Bureau performs examination of water with faucet of each house free and tells about the result.
(2) When we jointly carry out examination of water with cistern to receive and check in cooperation with Health and Social Welfare Bureau when safety of the quality of the water has a problem as a result of examination of water with faucet, and it is admitted that it is necessary about management of water tank Channel, instruction advises for installer of water tank Channel and urges. Examination of water is not included in the water supply method enforcement regulations,
(i) Thing that user for the quality of the water is highly concerned with
(ii) Plan equalization of user and services such as single-family houses
(iii) In consideration of examination of water being necessary, we became the regulations as Motoichi original correspondence to judge the management situation of water tank water supply.
In addition, there is no change in contents of managerial responsibility of water tank water supply installer based on the regulations ("the regulations about securing of drinking water which is hygienic by security in Yokohama-shi simple water supply water supply and small scale tray water tank water supply") of the water supply method and Health and Social Welfare Bureau jurisdiction.

Inquiry about water supply to Water Works Bureau customer Service Center

Water Works Bureau customer Service Center

Telephone: 045-847-6262 fax: 045-848-4281
※You run, and please be careful not to make any mistake

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The Water Works Bureau clean water part quality of the water section

Telephone: 045-371-5656

Telephone: 045-371-5656

Fax: 045-371-6942

E-Mail address [email protected]

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