Upload
della-spencer
View
221
Download
6
Embed Size (px)
Citation preview
Project of Capacity Building for Analysis and reduction measures of Persistent Organic
Pollutants in Serbia
(Hyogo Environmental Advancement Association )
June 2014
Measures for Securing Safety against PCBs
at Takasago West Port
2
1. Location of Takasago city
Himeji
Takasago
OsakaKobe
Akashi
Kansai Int’l Airport
The Sea of Harima
Awaji
Kaneka
Osaka Int’l Airport
2
3. Countermeasures to PCB sediments at Takasago West Port3-1 Background
1) In 1972 in Takasago West Port PCBs were detected in bottom sediments survey point:24 points, PCB concentrations: 4-3,300 mg/kg
2) Source of contamination a) PCBs were contained in wastewater discharged by Company M (Paper Mill) b) Kaneka (producing PCBs) may have discharged the wastewater to West Port
3) Implementation of Measures (Dredging of bottom sediments of West Port and solidifying dredged sand & soil) Build-up the solidified sand and soil near West Port → Takasago West Port Banking The 1st phase: September 1974 – March 1975 The 2nd phase: August 1975 – August 1976
4) Bottom sediment survey just after the dredging completed 40 survey points : ˂ 0.01 – 4.53mg/kg (tentative removal standard of bottom sediments : 10mg/kg)
5) Monitoring Takasago city and industrial firms (Kaneka and Company M) are continuously performing monitoring Monitoring : Survey twice a year the underground water, rainwater, ambient air in the vicinity of the banking and West Port → maintaining the levels of the lower quantitation limit or less
4
3-2 PCBs level of Takasago West Port
The Sea of Harima
PCB concentration of sediments at West Port : mg/Kg
5
3-3 The volume of the dredged soil of the banking
Items The 1st Phase The 2nd Phase Total
Dredging started Sept. 1974 Aug. 1975 -
Dredging completed Feb. 1975 Dec. 1975 -
All construction completed
Mar. 1975 Aug. 1976 -
Dredged area m2 45,000 194,000 239,000
Planned volume of dredging m3
110,000 170,000 280,000
Volume of dredged soil (wet weight)
112,000 189,000 301,000
Volume of embankment
- - 224,000
Volume of embankment (including covering soil)
- - 283,000
6
3-4 Dredging and construction schedule of West Port
The 1st Phase schedule
Sludge storage & solidification
banking
The 2nd Phase schedule
Dredging Carry out
constructingTaking out
Sand carrier Solidification curing pond
solidification
unloading
constructing
banking
Dredging Mud sending
Mud sending
sludge
Dredging vehicle with oozer pumpoozer pump
Solidification plant
Mud sending pipe
Mud sending pipe
Solid
ifica
tion
7
3-6 Cross-section of banking
• 技術委員会p14
Carbide residue etc.
1st phase banking
2nd phase banking
Concrete retaining wall
asphalt
asphalt
Mountain earth asphalt
Water impermeable sheet
9
工事体制3-7 Construction systemAdministrative Chief
Hyogo pref., Water Quality Control Division Director
Administrative Deputy Chief
Takasago MunicipalEnvironmental Pollution Prevention Office Director
(Water Quality & Commercial Fishing Sector)Person in charge: Deputy DirectorWater Quality Control Division
(Air Quality & Dust Sector) (Construction Sector)Person in charge: Deputy DirectorPort & Harbor Division
Water quality control Div.
Institute for Envi’tal Studies
Envi’tal Pollution Prevention Office
Air quality control Div.
Institute for Envii’tal Studies
Envi’tal Pollution Prevention Office
Port & Harbor Division
Kakogawa Civil Engineering Office
Municipalconstruction section
Duties-in-charge Duties-in-charge Duties-in-charge
1.Develop Monitoring Plan2.Measure water quality & sediments based on monitoring plan3.Manage & monitor secondary environmental pollution prevention facility4.Investigate fish & shellfish based on monitoring plan5.Anything required related with water quality and commercial fishing
1.Monitor prevention of scattering of dust
2.Measure PCB concentration in ambient air
3.Anything required related with air quality and dust
1.Maintain, manage & monitor construction work2.Supervise construction work3.Understand the present situation of construction work4.Supervise fishing net and ON/OFF of protector5.Supervise IN/OUT of ships6.Anything required related with construction work
Industrial firms
10
Person in charge: Deputy DirectoriviAir Quality Control Division
3-8 Management after taking countermeasures
● : underground water● : air● : rainwater, sea water or river water
banking
Company M
Takasago West Port
Kaneka
11
4. Background for taking measures to permanently stabilize & assure its safety
1. July 2005 Formulate “Takasago Regional Development” Plan Safety of banking became controversial due to the plan2. June 2006 Establish “Technical Committee on PCB banking” Five academic experts were nominated3. Sept.2007 Technical Committee on PCB banking submitted Report Validate the safety of the banking. Study measures to permanently stabilize the PCB banking4. Mar. 2008 Establish “Council for Promoting Redevelopment of Takasago West Port” Five academic experts, two administration officers, seven citizen representatives and three related company people were selected Study the improvement of port and harbor, countermeasures to permanently stabilize the PCB banking, water amenity space and access plan Hold a meeting to explain to local residents and approved containment method5. Apr. 2009 Council for promoting redevelopment of Takasago West Port submitted Report 6. June 2010 Establish “Technical Committee on Redevelopment of Takasago West Port” Six academic experts were nominated7. Mar. 2011 Technical Committee on Redevelopment of Takasago West Port submitted Report8. Feb. 2013 Construction work for permanently stabilizing PCB banking started (Management of design and construction by Construction sector, Hyogo pref.) 9. May 2015 Construction work for permanently stabilizing PCB banking completed
12
4-2 Technical Committee
1. Technical Committee on PCB banking at Takasago West Port Chair person: FUJITA Masanori (prof. emeritus at Osaka Univ.) member: KIMBARA Kazuhide (associate prof., Okayama Univ.) TOKIDA Kenichi (prof., Graduate School of Eng., Osaka Univ.) NOMA Yukio (Director, National Institute for Environmental Studies) MICHIOKU Kohji (prof., Graduate School of Eng., Kobe Univ.)
2. Technical Committee on redevelopment of Takasago West Port Chair person: FUJITA Masanori (prof. emeritus at Osaka Univ.) member: KITAMURA Yasutoshi (prof. emeritus at Kobe Univ.) DEGUCHI Ichiro (prof., Graduate School of Eng., Osaka Univ.) TOKIDA Kenichi (prof., Graduate School of Eng., Osaka Univ.) MICHIOKU Kohji (prof., Graduate School of Eng., Kobe Univ.) KAWAI Hiroshi (prof., Kobe Univ.)
* The title mentioned is at the time of nomination
13
4-3 Report by Technical Committee on PCB banking at Takasago West Port
1. Validate the safety of banking (1) Survey 1) Analysis: a. banking (boring 2 points)→soil investigation, PCB analysis b. surrounding area of banking (bored 6 points for 20m) →soil survey & analysis 2) Confirmation: monitoring data up to date or documents like drawings
(2) Result : No PCB leakage was found in the surrounding area. No possibility of PCB leakage due to complete impermeable sheet covering solidification soil containing PCB.
(3) Study on the structure of banking 1) Embankment failure In the event of large-scale earthquake, liquefaction occurs and may lead to slope failure (partially collapse) 2) Soil subsidence : Embankment is subsided. No need to worry about the target area for further unbalanced subsidence 3) Tsunami : Tsunami with an estimated maximum height will not reach the banking 4) Tidal wave : High wave with an estimated maximum height will not erode the slope face much 5) Heavy rain : No flood damage of banking due to heavy rain and tidal wave with estimated maximum level 6) Revetment: Strength poverty is found partially and have the potential for breakdown in the event of a large-scale earthquake
2. Permanent countermeasures of banking Studied 3 cases as countermeasures and adopted the containment measure because of the lowest risk14
4-4 Measures to permanently stabilize & assure its safetyCountermeasures shown in the Committee ReportCountermeasures shown in the Committee Report
A. Remove and dispose all B. Decomposition treatment C. ContainmentA1 Remove all PCB banking, decompose and dispose at final disposal area
Period 20 yrs (decomposition & reclamation) 10 yrs (reclamation)
Period 20 yrs
Period 2 yrs
Cost $1.57 bil (decomposition & reclamation) $400 mil (reclamation)
Cost $1.5 bil
Banking Carry out
Banking
Banking
Banking
Banking
Carry out
Carry out
decompositionDecomposition at neighboring area
Backfill at banking
Final disposal site
Final disposal site
Final disposal site
A2 Remove all PCB banking and dispose at final disposal area without decomposition
B Remove all PCB banking, decompose at neighboring area and backfill at the original banking (or dispose at final disposal area
Cover upper portion
Good quality earth
Covering
C1 Cover the upper portion of banking
C2 Cover the upper portion and construct water impermeable underground earth retaining wall
Water impermeable underground earth retaining wall
Cost $75mil (covering $40 mil & construction $35 mil)
Non woven fabric sheet+ water Impermeable sheet+ non woven fabric sheet
Image of covering lid for excavating site
Image of covering lid for excavating site
10t box car
Evaluation:1. Secure facilities with effective acceptance system is the problem to be solved2. Scattering of dust to the surroundings is anticipated during the long construction period
Evaluation : 1. Construction of large scale treatment facility is necessary2. Scattering of dust to the surroundings is anticipated during the long construction period
Evaluation : 1. Completion of the work is expected in short period and no risk for scattering of dust2. Plan C2 ensures safety in the event of a large scale earthquake etc.
* Reinforcement of surrounding retaining wall is necessary in any countermeasures to be taken
Existing asphalt covering
Solidified banking soil
15
4-5 Containment method
Covering top layer = water impermeable sheet + covering soil
covering soil Asphalt layer
North SideSouth Side
2nd Phase Solidified soil containing PCB
1st Phase Solidified soil containing PCB
Reinforce retaining wall
Carbide residue etc.
Supporting ground
Liquefaction layerWater impermeable underground earth retaining wall
Publ
ic W
harf
Seas
ide
road
city
road
Countermeasure construction work16
4-6 Overview of PCB banking countermeasure project
Water impermeable underground earth retaining wall
Covering of upper portion
Reinforce retaining wall
Reinforce retaining wall
Pressing banking
Water impermeable underground earth retaining wall
Coveringsoil
Solidified soil
17
4-7 Success factors of the PCB banking countermeasure project
1.Transparency ・ Technical committee or Council for Promoting Reconstruction was held with open doors including the mass media ・ Any documents or the minutes of the proceedings of the committee were available in internet ・ Takasago city issued public relations magazines ・ Meetings to explain to local residents were held →Opinions of the public were reported and studied at the committee
2. Soliciting evaluations from the viewpoints of academic experts ・ Chose the influential and the right person (Hyogo prefecture) ・ Based on the data (soil survey, soil analysis or preserved documents etc.), experts evaluated from the academic point of view ・ Consider in a wide range free from conditions like construction cost etc. and suggested the best strategy →offer persuasion
3. Administrative guidance ・ Give priority to gain the understanding of local residents (Chose citizen representative as Council member. Held meeting and explained to local residents ) ・ The administrative body (prefecture) supervised the design and managed the countermeasure construction work ・ Build reliability between the administrative body and related industrial firms18