瑞穂町図書館/温故知新 ― 瑞穂町を旅する地域資料

瑞穂町と横田基地

Ⅲ 基地と住民生活 Base and Residents' Living Condition

1.騒音問題 Noise Pollution

 横田基地から発着する航空機の騒音調査は、昭和42年町議会騒音対策特別委員会が実施したものが最初の調査である。その後、町議会基地対策特別委員会が担当するようになり、昭和48年10月から東京都による24時間の固定調査が開始された。場所は箱根ケ崎浄水場付近であった。平成9年4月より現在の瑞穂町農畜産物直売所「ふれっしゅはうす」に移設した。The first formal investigation of noise levels of aircraft arriving at and departing from the Yokota base was conducted by our town council's Special Committee on the Aircraft Noise Abatement Countermeasures in 1967. Subsequently, the town council's Special Committee on the Military Base Affairs took over this responsibility, and from October 1973 the Tokyo Metropolitan Government commenced 24-hour-a-day, year-round study to measure sound levels at a fixed site. The site chosen for this measurement was near the Hakonegasaki water purification plant. In April 1997, it was relocated to a new site, known as "Fresh House", which is the MIzuho farmers' produce stand.
 町単独では、昭和60年12月に二本木670番地の瑞穂町立第三小学校(以下「三小」と言う。)の屋上に設置した。当時はNLPが実施されるたびに、役場屋上に移動し騒音調査を実施した。その後、平成12年3月に三小から役場屋上に移設した。Under its own initiative, the town itself set up a separate measuring site at the Third Elementary School (hereinafter referred to as the "3rd E-School"), at the address of 670 Nihongi, in December 1985. In those days, whenever the NLP was carried out, the staff temporarily moved the device to the rooftop of the town office to measure the noise for the study. Subsequently in March 2000, the device was relocated from the 3rd E-School to the rooftop of the town office.
 町独自の測定は1か所であったが、平成11年4月石原慎太郎氏が東京都知事に就任し、横田基地の軍民共用化が浮上すると、航空機による被害が甚大な瑞穂町としては、より正確な情報と町独自の分析の必要性から同年12月に箱根ケ崎民家(以下民家と言う。)と消防団第四分団詰所(以下詰所と言う。)に、実音モニターつきの測定器を設置した。Initially, the town's own measurements had been made at a single site. However, in April 1999 Shintaro Ishihara took office as the Governor of Tokyo, and suggested the civil-military dual-use of Yokota Air Base. Consequently, Mizuho – which had already suffered enormous damage from aircraft – was impelled to obtain more accurate information to enable the town to conduct its own independent data analysis. In December of the same year, the town installed a measurement device with sound monitor at a private house in Hakonegasaki (hereafter referred to as ‘the house’) and at the fire brigade's fourth squad station (hereafter referred to as ‘the station’).
 平成15年8月に瑞穂町の要請に基づき基地北側にあるヘリパッドが南に約1.7kmの場所へ移動したことに伴い、殿ケ谷上空の飛行回数が減ったことから、近年市街地上空を飛行するヘリコプターの騒音測定を行うべく、詰所に設置していた測定器を役場屋上へ移設した。Because the number of helicopter flights over Tonogaya area decreased with the move of the helipad(s) at the north of the base to a location approximately 1.7 km to the south at the request of Mizuho in August 2003, the device that had been installed at the station was relocated more recently to the town office rooftop in order to measure the helicopter noise over the urban area.
 平成17年10月には住宅防音工事対象工事区域である第1種区域の指定の見直しがなされた。In October 2005, designation of the class 1 area (which is an area intended for residential soundproofing installation) was reviewed.
 なお、平成24年10月には騒音測定器を更新し、平成25年度から適用されている新環境基準に拠る測定を行っている。In addition, the noise-measuring device was updated in October 2012, so the subsequent measurements meet the new environmental standards adopted in the 2013 fiscal year.

(ア)測定概要(a) Summary of the noise measurement data
 町で2台、都で1台、国(北関東防衛局)で3台の計6台の固定式により24時間航空機の騒音測定を行っている。町独自調査は2か所で、民家と役場屋上の測定器は秘書広報課の中央局PCとオンライン化されている。朝及び随時にオンラインによるデータ収集を行い、分析(航空機以外の騒音の削除やヘリコプター騒音の確認)及び集計作業をしている。The aircraft noise is measured over 24 hours a day using a total of six fixed-type units: two units owned by the town, one by Tokyo Metropolitan Government and three by the national government (North Kanto Defense Bureau). The town's own investigation is being made at two sites (the house and the office rooftop, and the measuring devices are linked online to the central office computer of the Secretary and Public Affairs Department. Data collection is made online in the morning and at any time, followed by analysis (by deleting non-aircraft noise and confirming what is helicopter noise) and then data processing is undertaken.

(イ)測定条件(b) Measurement conditions
旧環境基準(平成25年3月まで)
 明らかに航空機騒音と認められるピークレベル70dB(A)以上の騒音
Old environmental standards (up to March, 2013)
Noises clearly recognized as aircraft noise with a peak level of 70 dB (A) or greater.
新環境基準(平成25年4月以降)
 暗騒音(ここでは航空機以外の騒音)より10dB(A)以上大きい航空機騒音
New environmental standards (April 2013 or later)
Aircraft noise of 10 dB (A) or greater than the background (excluding the noise of other aircraft)
 町では過去のデータとの比較のため、新基準への移行後も新旧両方の基準に基づいた集計を行い、町のホームページで公開している。For comparison with the previous data, the town has been processing the data according to both the new and old criteria, even after the transition to the new standards. The results are open to the public on the town's homepage.

(ウ)測定場所(c) Measurement locations

地区
Area
所在地
Location
用途地域
Zoned
設置年月日
Installation Date
設置者
Installer
備考
Note
箱根ケ崎
Hakonegasaki
箱根ケ崎地内
(民家)
Within Hakonegasaki area
(private house)
第一種低層住宅専用地域
Class 1specified for low-rise residential area
H11.12.28
(H.24.9.28更新)
Dec. 28, 1999
(Renewed on Sep 28, 2012)

MizuhoTown
役場にオンライン化
On-line system introduced to Town Office.
箱根ケ崎
Hakonegasaki
箱根ケ崎2335番地
(役場屋上)
2335 Hakonegasaki
(Town Office Roof)
近隣商業地域
Neighborhood commercial district
H19.5.16
(H24.9.28更新)
May16, 2007
(Renewed on Sep 28, 2012)

MizuhoTown
H12.3.10に第3小学校から移動、その後H19.5.16に第四分団詰所から移動
Relocated from the 3rd ElemRelocated from the 3rd Elementary School on March 10, 2000. Later transferred from the Fire Brigade's 4th Squad Station on May16, 2007. Relocated from the 3rd Elementary School on March 10, 2000. Later transferred from the Fire Brigade's 4th Squad Station on May16, 2007.

※その他、防衛省(北関東防衛局)が、滑走路北側、栗原地区及び二本木地区に各1台、東京都が箱根ケ崎612(ふれっしゅはうす)に1台、固定式の騒音測定器を設置している。* In addition, three more fixed-type noise measuring devices have been installed: two units, one on the north side of the runway and the other in the Nihongi of Kurihara district, by the Ministry of Defense (North Kanto defense station), and one unit by the Tokyo Metropolitan Government at 612 Hakonegasaki (Fresh House).