2. A Brief History of Chiba Prefecture Waterworks
Transcription
2. A Brief History of Chiba Prefecture Waterworks
2. A Brief History of Chiba Prefecture Waterworks such issues as how to acquire raw water, and how to save on construction costs. With the agreement of the communities concerned an investigation committee consisting of specialists, assemblymen, and the governor, as chairman, was established in April 1933. It held discussions on the project, and proposed that the prefectural waterworks system should be designed for rational management, with emphasis on technology and economics. In May 1933, an extraordinary session of the assembly adopted this proposal unanimously. In June, permission for construction of the Chiba Prefectural Waterworks. On March 31, 1934, the Government granted permission. Bonds had already been issued by the Ministry of Finance to cover expenses of works was at last begun. ●Basic Plan Chiba Purification Plant (presently the Chiba Pump Station) elevated tank ■The Dawn of Public Waterworks ●Background In the 1920s only one percent of the population of Chiba Prefecture had access to public water. At that time, people living in the region along Tokyo Bay, and between the Edo River and Chiba City, took water directly from wells and rivers. Water from both of these sources was of inferior quality. According to a 1930 report, water at twothirds of the wells tested was unsuitable for drinking. Epidemics occurred frequently. In light of this situation thirteen communities in the area, including the city of Chiba, and the towns of Ichikawa and Matsudo, called for introduction of modern waterworks. ●Establishment of Prefectural Waterworks In response to these circumstances, then prefectural governor F. Okada prepared a development plan for the belt along the Edo River. A main foundation of the plan was the waterworks system, which was assessed from all possible angles, especially with respect to the advantages and disadvantages of operation of the system by the prefecture. This led to a broader waterworks development plan which covered all districts concerned, and dealt with The basic plan called for a maximum daily water supply of 37,500m3 to serve the needs of population of 250,000. The project was to be completed by the year 1951, at a cost of 3.5 million yen. Water intake sites were located to the west in Matsudo town, by the Edo River (the current site of the Kogasaki Water Purification Plant) with plans calling for intake of 27,000m 3/day, and to the east in the village of Miyako, Chiba district, where intake of 10,500m3 from underground sources was projected (the current site of the Chiba Pump Station). In June, 1936, water service was commenced to Chiba City where facilities were first completed. As construction progressed, the other communities were supplied one after another, with construction of the entire system completed by December, 1941. ■First Expansion Project After recovering from the devastation caused by World WarⅡ, the region served by the waterworks developed rapidly, and water demand rose sharply. In order to alleviate shortages and stoppages in supply, which were already occurring in the summer of 1952, the first expansion project was initiated. However, the acquisition of additional water sources proved difficult, and for some time water shortages continued. In April, 1955, an opportunity to acquire water rights for an intake of 0.8m 3 /second from the Edo River was created. Rights were granted in November, and construction commenced in April, 1956. This expansion project was designed to serve the needs of a population of 458,000 with a maximum water supply of 123,750m3 by the year 1965. In fact, this urgent undertaking was completed by 1962. The major objectives of the project were to construct Kuriyama Water Purification Plant (Kuriyama, Matsudo City) with treatment capacity of 66,000m 3/day that would take water from the Edo River, Ichikawa Water 33 November, 1966, giving the Prefectural Waterworks Bureau a daily maximum capacity of 271,000m3. ■Third Expansion Project Purification Plant with capacity of 9,000m 3/day and Omiya Water Purification Plant with capacity of 6,750 m3/day that would take water from underground, to acquire Imai Water Purification Plant with capacity of 4,000m3/day and to increase the maximum supply capacity of Chiba Pump Station by 500m3/day to supply water to Ichikawa, Funabashi and Chiba areas. In June, 1958, water service from Kuriyama Water Purification Plant was started to a segment of these areas and to the entire areas by 1960, thus eliminating the shortage and stoppage that have plagued the region for so long. The total cost of the project was in excess of 2,760 million yen. The maximum supply capacity of the total project reached to 123,750m 3/day, which was approximately three times larger than that of earlier facilities. Even though work on the second expansion project was completed a year ahead of schedule, urbanization of the region accelerated at such a pace that the then existing water service facilities would soon be incapable of handling increasing demand. Accordingly, the third expansion project was prepared and approved in December, 1961, and work commenced in April, 1965. The project proposed to serve a population of 1,214,000 by creating an additional daily water supply capacity of 270,000m3 by the year 1970. The major components of the project were construction of the Inba Intake (located in Usuida, Sakura City), to take raw water from Inbanuma Lake, a part of the Tone River system, construction of the Kashiwai Purification Plant (Kashiwai, Chiba City) with a capacity of 270,000m3, and construction of Honda Pump Station (Honda, Chiba City), for stabilization of water supply to districts including the cities of Chiba, Funabashi and Ichihara, as well as to strengthen the water supply capacity of the existing Kuriyama Purification Plant and the Funabashi and ■Second Expansion Project Rapid enlargement of the Keiyo coastal industrial belt along Tokyo Bay caused further high growth in the region. By 1961 the population had increased 385,000, and daily maximum supplied water had reached 125,000m3. Water supply demand exceeded the limits of the first expansion project before the target year 1965, making water stoppage inevitable. Accordingly, the second expansion project was approved in March, 1962, and new construction begun in April. The second expansion project proposed to serve a population of 694,500 by creating an additional supply capacity of 147,250m3 by the target year 1967. Major programs implemented under this project were addition of a water purification facility with treatment capacity of 12,000m3/day at Kuriyama Plant, installation of service pipes to Chiba City, construction of an underground water purification plant with 12,000m3/day capacity in Anegasaki, Ichihara City and increase the capacity of the existing underground purification plants by 15,250m3/day. The funds expended on this project were in excess of 6,030 million yen, and all facilities were completed in 44 Sonno Pump stations. The third project was completed in March, 1972. The project cost amounted to 15.3 billion yen and resulted in a daily maximum capacity of 541,000m3. ■Fourth Expansion Project To cope with the growing water demand, the fourth expansion project was approved in March, 1971 and commenced in April the same year. Subsequently, the project has been revised three times to comply with the regulations on underground water under the Pollution Control Ordinance of Chiba Prefecture as well as to cope with the change of water intake points established to receive water supply from Kimitsu Water Supply Authority and the lower water demand slowed down by the Aggregate Demand Management Policy of the national government. The final approval was issued for the project in March, 1980, with the goal to meet the water needs of a population of 2,794,000 by 1993 with the maximum demand of 1,350,000m3/day. Until the project was merged with the Hokuso Area Waterworks in March, 1982, the capacity of Kashiwai Purification Plant was increased by 285,000m3/day by the construction of Kioroshi Intake Station (Inzai City) that takes water from the Tone River, the capacity of Kogasaki Purification Plant was increased by 33,000m3/day, and the maximum water supply capacity was expanded to 395,000m3/day by receiving water supply of 77,000m3/day from the Kita-Chiba and the Kimitsu Water Authorities at Shonan Pump Station (Shonan, Higashi Katsushika County) and Anegasaki Pump Station (Yushudai, Ichihara City). The project costs amounted to 129,330 million yen and resulted in total daily capacity of 936,000m3. ■Hokuso Area Waterworks Vigorous land development and housing project construction on the part of the prefecture in response to population increases brought on by the development of the coast industries belt and the spill-over of metropolitan growth into Chiba prefecture resulted in disorderly urbanization of this area, and a shortage of public facilities of all types. The prefectural government responded to this situation by planning integrated construction of necessary public facilities in future urban developments. The results are seen in Narita New Town (Narita City), Chiba New Town (Funabashi City, Shiroi Town, Inzai City, Motono Village, and Inba Village), which were developed in conjunction with the construction of the New Tokyo International Airport. Water service to the new towns, and the large region surrounding the new international airport, were undertaken by the prefecture at great cost. Acquisition of adequate water supplies to meet high water utilization in this area was the primary goal of the new water supply project, which commenced in 1970. This project proposed to serve a population of 400,000 by creating a daily maximum water supply of 190,000m3 by the target year 1986. As mentioned, this project was united with the fourth expansion project for the Keiyo area on March 31, 1982. The major components of the Hokuso waterworks project were the construction of the Kioroshi Intake (at Kioroshi, Inzai City) in collaboration with the fourth expansion project at Keiyo, to take water from the Tone River system, the transport of raw water under pressure to Hokuso Purification Plant (Motono Village) and the supply of purified water from there to Chiba New Town directly and Narita New Town including the New Tokyo International Airport, via Narita Pump Station. This project, the cost of which has exceeded 22 billion yen, has succeeded in supplying a daily maximum of l26,700m3 water. ■Combined Fourth Expansion Project efficient operation of facilities, to provide equitable service charges and stabilized management and to promote more efficient administration. On March 31, 1982, the new enterprise was approved, and on April 1, the projects were combined under the name Chiba Prefectural Waterworks (Combined Fourth Expansion Project). The project had a goal to meet the water need of a population of 3,194,000 by 1993 with the maximum demand of 1,540,000m3/day. Major plans of the combined project were the construction of Takataki Intake Station (Yourou, Ichihara City) that takes water from Takataki Dam on the Yourou River water system, the construction of Fukumasu Water Purification Plant (Fukumasu, Ichihara City) that treats water of 90,000m3/day, the addition of water reservoirs at Kashiwai and Hokuso Water Purification Plants and expansion of Honda Pump Station and Anegasaki Pump Station. Over 145,300 million yen was invested in this project, and the maximum supply capacity increased to 1,244,100m3/day in 1993. ■Chiba 21st Century New Waterworks Project In 1993, which was the goal year of the combined fourth expansion project, a plan for the Chiba 21st Century New Waterworks Project was developed to meet the expectation of users for waterworks with higher quality, based on ① the growth of water demand slowed down by the collapse of the "bubble" economic boom, ②the superannuated Kogasaki Water Purification Plant constructed at the time of the foundation of the Waterworks, ③the needs for water sources along the Boso Channel, and ④ the strong needs of citizens for safe and quality water, and other factors. The Project was approved by the Ministry of Health and Welfare on March 31, 1994 and started in April the same year. The goal of this Project is to serve a population of 3,238,000 by 2010 with the maximum water supply of 1,440,000m3/day, which is lower than the goal of the previous project by 100,000m3. Major plans of the Project are construction of Edogawa Water Purification Plant (presently : Chiba Nogiku no-sato Purification Plant) by which the role of the obsolete Kogasaki Plant and Kuriyama Plant would be replaced, construction of a new water purification plant for a new water source to be secured along the Boso Channel, and sequential introduction of an advanced water purification system to all water purification plants to supply safer water with higher quality. In the past the bureau had managed the Keiyo and Hokuso waterworks project separately, but it was decided to integrate the two area so as to more effectively utilize water sources, to promote more 55 Comparison ofof Express Project Project and Daily Water Supplied Camparison Express and Daily Water Supplied 160 (Actual Wate Supply up to FY 2013) (Actual Water Supply up to FY 2013) Unit:10,000m3/day 4rd Expansion(combined) Chiba 21st century New waterworks Project 150 4rd Expansion for Keiyo area 140 130 120 110 Actual Water Supply 100 90 80 70 3rd Expansion for Keiyo area 60 50 40 2nd Expansion for Keiyo area 30 W/S established in Hokuso area 1st Expansion for Keiyo area 20 10 0 1952 1957 1962 1967 1972 1977 1982 1987 1992 1997 2002 2007 2012 Established and Approved Projects Name of Water Supply System Item Keiyo area waterworks Hokuso area waterworks Original project Current project ( ) Works Establishment 1st Expansion 2nd Expansion 3rd Expansion 4th Expansion Establishment (4th Expansion/Combined) Chiba 21st century New waterworks Project Mar. 31. 1934 Nov. 10. 1955 Mar. 26. 1962 Dec. 28. 1964 Mar. 31. 1971 Mar. 31. 1970 Mar. 31. 1982 Mar. 31. 1994 Oct. 3. 1941 Date of authorization Aug. 24. 1959 Mar. 31. 1970 Mar. 30. 1974 Mar.29. 1978 Dec. 28. 1960 May. 9. 1979 Mar. 31. 1982 Mar. 3. 1980 discontinued Mar. 31. 1982 discontinued Target year 1951 1965 1967 1970 1993 1986 1993 2010 Population in service area(Persons) 333,300 870,000 1,067,310 1,505,000 2,871,000 400,000 3,271,000 3,304,000 Population served(persons) 250,000 458,000 694,500 1,214,000 2,794,000 400,000 3,194,000 3,238,000 Percentage of population served 75 53 65 80.7 97.3 100 97.6 98 Max. daily supply (㎥) 37,500 123,750 271,000 541,000 1,350,000 190,000 1,540,000 1,440,000 Max. daily supply per capita(ℓ) 150 270 390 446 483 400 482 445 ※ Construction cost(1,000yen) ※ Date supply started 3,500 June 1936 Edo river 2,767,000 5,943,000 Nov. 1955 Edo river Aug. 1964 Edo river 15,294,000 129,332,000 22,004,000 145,383,000(965,735,432)planned July 1968 Jan. 1972 Tone river Apr. 1971 Edo river Underground water Underground water Underground water Inbanuma lake Tone river Underground water Inbanuma lake Water sources Tone river Apr. 1982 Edo river Underground water Tone river — Edo river Tone river Inbanuma lake Inbanuma lake Yourou river Yourou river Yourou river Water received Water received Water received (Kita-Chiba and (Kita-Chiba and Boso-dousuiro P.P. Kimitsu W/S) Kimitsu W/S) (Kita-Chiba and Kimitsu W/S) Kogasaki P.P. Kuriyama P.P. Kuriyama P.P. Kashiwai P.P. Kogasaki P.P. Hokuso P.P. Kashiwai P.P. Kashiwai P.P. Chiba P.P. Water purification plants expanded/constructed Ichihara P.P.(expanded) (expanded) Anegasaki P.P. Kashiwai P.P. Fukumasu P.P. Hokuso P.P. (expanded) Hokuso P.P.(expanded) Omiya P.P. Imai P.P. (acquisition) (expanded)(expanded) (expanded) Edogawa P.P. Boso-dousuiro P.P. Figures with the 6 ※ mark are based on the actual results. ■The business promotion After receiving authorization to operate water services (authorization to change the founding business) in accordance with the "Chiba 21st Century New Waterworks Project," Chiba Prefectural Waterworks has business promotion ■Theworked since to provide a variety of services such as the management of water purification as outlined After receiving authorization toplants operate water Due to the protracted economic slump following the in the "Chiba Waterworks Medium-Term services (authorization to change business) collapse of the Prefectural bubble economy inthe thefounding 1990s and advent Management (2006-2010)." in with theand "Chiba Century New of aaccordance decliningPlan birth rate aging21st population, Japan is Some water services have been suspended because of Waterworks Chiba Prefectural Waterworks has transitioning Project," from a social and economic structure based the slowdown of provide the increase in water supply demand, since worked to a variety of services such as on mass production to one that emphasizes quality, caused by the protracted economic slump andasincreased the management of water purification outlined requiring the reorganization of theplants management of water awareness. However, the water in the conservation "Chiba Waterworks Medium-Term various fields. Prefectural supplied population is still Waterworks increasing, and water supply Management Plan (2006-2010)." The Chiba Prefectural Bureau’s 2011 demand will continue to increase over the next 10ofyears Some water services have been suspended because of Medium-Term Management Plan for the period 2011 according predictions for water supply demand based the slowdown of basic the increase in water demand, to 2015 settofive objectives in eachsupply business field, on latest Because ofand thisslump expected increase, caused the data. protracted economic and setting increased andthe theby Bureau is effectively efficiently in there is a need to make continuous plans for facility water awareness. water motion conservation the policies and initiatives However, necessary the to achieve management and water sources. supplied population is still increasing, and water supply these goals. Therefore, the "Chiba Prefectural demand will continue to increase over the plan, next Medium10 By steady implementation ofWaterworks this weyears will Term Management Plan 2011" was developed to inherit according to predictions for supply demand based respond appropriately to water the changing times, and the accomplishments of thefull medium-term management on the latest data. Because of and this active expected increase, continue to support the lifestyles of plan that expired at the end of March 2012, and there is acitizens need toasmake plans and for further facility Chiba’s well continuous as provide safer highercultivate theseand accomplishments. management water sources. quality water, with the aim of being a sustainable lifeline Through this new business operations plan, Therefore, thebusiness "Chiba Prefectural Waterworks Mediumwith a stable foundation that ispolicy suitable for we an will continue to provide customers with a stable supply Term Management advanced society. Plan 2011" was developed to inherit of and good quality water. thesafe accomplishments of delicious the medium-term management plan that expired at the end of March 2012, and further cultivate these accomplishments. Through this new business operations policy plan, we will continue to provide customers with a stable supply of safe and good quality delicious water. promotion of quality water production, etc.) Objective 2: Waterworks dedicated to customers through high- quality service and technology ③ Promote customer service (Expansion ofofgood public relations; exploration new promotion quality quality water water production, production etc.) of etc.) customer Objective 2: payment methods) ④ Pass technology onto the next generation Waterworks dedicated to customers through high- quality quality (Conduct practical technical training) service and technology Objective 3: customer service ③ Promote Waterworks during earthquakes other of emergency (Expansion of of public public relations; relations;and reflection exploration customer of new situations feedback customer in payment business methods) operations) ⑤ Pass Improve crisis management system ④ technology onto the next generation (Strengthen and improve emergency water supply (Conduct practical technical training; training) consider system; reinforce initial response system) Objective development 3: of hands-on training facilities) ⑥ Secure flexibility systemand in case of emergency emergency Objective Waterworks 3: water during earthquakes other (Maintenance of backup system between water situations Waterworks during earthquakes and other emergency purification plants and pump stations) ⑤ situations Improve crisis management system Objective 4: crisis ⑤ Improve (Strengthen and management improve emergency system water supply Eco-friendly waterworks system; (Strengthen reinforce and improve initial response emergency system) water supply ⑦ Promotion of environmental measures ⑥ Secure system;water reinforce flexibility initialsystem response in case system) of emergency (Promote energy conservation; utilize renewable ⑥ Secure (Maintenance water flexibility of backup system system in case between of emergency water energy) purification (Maintenance plants of backup and pump system stations) between water Objective 5: Objective purification 4: plants and pump stations; security of Waterworks with a maintainable, stablesuppliers) management Eco-friendly water flexibility waterworks system with water ⑧ Secure and cultivate human resources Objective ⑦ Promotion 4: of environmental measures (Organized employment of human resources; employee Eco-friendly (Promotewaterworks energy conservation; utilize renewable development) training and skill ⑦ Promotion energy) of environmental measures ⑨ Improve efficiency Objective (Promote 5: operation energy conservation; utilize renewable (Secure efficient business operations; promotion of Waterworks stable management energy) with a maintainable, computerization) ⑧ Secure Objective 5: and cultivate human resources ⑩ Reinforce management system (Organized employment of human resources; employee Waterworks with a maintainable stable management (Cost reduction attentive quality reassurance; andcultivate skill development) ⑧ training Secure and humantoresources of stable revenue and financial ⑨ Improve operation efficiency security (Organized security of human resources;reform) employee (Secure and efficient operations; promotion of training skill business development) ⑨ computerization) Improve operation efficiency ⑩ management system Reinforce (Secure efficient business operations; promotion of (Cost reduction attentive to quality reassurance; computerization) (2010) Admitted water sources security ofmanagement stable revenue and financial reform) ⑩ Reinforce system (Cost reduction attentive to quality reassurance; Water Rights Intake Facilities security of stable revenue and financial reform) Rivers Water Sources Introduction of Advanced Treatment System (Ozone Generators) This system uses ozone, which has strong oxidation abilities, to break down organic matters that might affect water quality. The system then uses active carbon to remove these organic materials through absorption. Introduction of Advanced Treatment System (Ozone Generators) <Basic Objectives Main Initiatives of the Chiba This system uses and ozone, which has strong oxidation Prefectural Waterworks Medium-Term Management abilities, to break down organic matters that might Plan 2011> affect water quality. The system then uses active carbon Objective to remove 1:these organic materials through absorption. Waterworks that provide safe, good quality water ① Secure a safe water supplyInitiatives of the <Basic Objectives and Main the "Chiba Chiba (Updating water purification plant andManagement pump station Prefectural Waterworks Medium-Term Plan facilities, 2011> 2011"> updating and maintenance of pipes.) ② Provide Objective 1: safe, good quality water (Introduction of the advanced system: Waterworks that provide safe, good treatment quality water ① ② Secure a safe water supply (Updating water (Stabilization of the purification water source; plant and renewing pump station water plant and station facilities) facilities, purification updating andpump maintenance of pipes.) Provide safe, good quality water (Introduction of the advanced treatment system, system: Admitted water sources(m /sec) (m /day) 3 3 (Purification Plant) (2014) Water Rights Intake Facilities Rivers Water Sources Edosources River (2010) 1.060 Yagiri Intake Facilities Admitted water (㎥/ s) (㎥/日) (Purification Plant) Edo River From agricultural use 0.470 258,200 (Chiba Nogiku-no-sato P.P, 1.0601.460 EdoNaka River River, EdoRiver Kuriyama P.P) Water Rights Yagiri Intake facilities Intake Facilities 0.484 Naramata Dam Rivers Water Sources 258,200 (Chiba Edo River Nogiku-no-sato (Purification Plant)P.P., From agricultural use 0.470 3 3 (m /sec) (m /day) Kuriyama P.P.) Naka River, Edo River 0.976 Tone River salinity 2.070 178,800 Inba Intake facilities barrier (Kashiwai P.P facilities east side) Edo River 1.060 YagiriIntake Intake Facilities Tone River Inba 2.070 178,800 Edo River From barrier agricultural use Nogiku-no-sato P.P, 0.470 258,200 (Chiba salinity (Kashiwai P.P. east side) Kuriyama P.P) 1.460 Tone River Naka Tone ToneRiver, RiverEdoRiver salinity Tone River River Kioroshi barrier 1.4101.410 Kioroshi Intake IntakeFacilities facilities salinityKawaji barrier (Hokuso P.P, dam 1.9691.969422,200 361,600 (Hokuso P.P., Kawaji dam Kashiwai P.P west west side) side) Naramata dam 1.5100.484 Kashiwai P.P. Tone River salinity Inba Intake facilities Yunishigawa dam 2.070 178,800 Yunishigawa barrier dam 0.325 (Kashiwai P.P east side) Takataki Intake Intake Facilities facilities Yourou Takataki Takataki dam dam 1.1001.100 95,000 Yoro River Takataki 95,000 (Fukumasu P.P.) Tone River Tone River River salinity (Fukumasu P.P) barrier 1.410 Kioroshi Intake Facilities Naramata dam 0.484 Kashiwai P.P west side) Yunishigawa dam 0.325 Takataki dam 1.100 10.348 893,600 TotalTotal Kawaji dam 11.049 1.969954,200 361,600 Yoro River Total 95,000 (Hokuso P.P, 7 Takataki Intake Facilities (Fukumasu P.P) 10.348 893,600 77