sewage treatment system in seoul - 東京都政策企画局€¦ · sewage treatment system in...

Sewage Treatment System in Seoul

Oct 2016

Hunmo Jeong

Sewage Treatment Facilities Division

Seoul Metropolitan Government

e-mail : [email protected]

Development Plans2

Important Promotion Affairs in the Future3

Contents

Current Status of Sewage Treatment System1

Ⅰ. Current Status of Sewage Treatment System

Description of Sewerage System

• Area Served : 605.33 ㎢

• Population : 10.44 Million

• Drainage area : 4 big areas

• Sewer length : 10,297km

• Treatment Centers : 4

• Served ratio : 100%

Organization of Sewerage Management System

Sewerage Planning Division,Flood Control Division

25 Gu, 10 persons × eachJungnang Nanji Tancheon Seonam

Sewage TreatmentFacilities Division

Construction andTraffic Bureau

Seoul MetropolitanGovernment

25 District Offices

Water Recycle & Safety Bureau

Water ManagementPolicy Division

Water ReclamationPlanning Division

River ManagementDivision

4 Sewage Treatment Centers, 547 persons

Budget for Sewerage System

• Special account for sewerage works

• Budget (2015)

- Revenue : 733 billion won (USD 657 mil)

- Expenditure : 733 billion won (USD 657 mil)

Sewer Maintenance : 399 billion won (54.4%)

Operation and Maintenance of Sewage Treatment

Centers(STC) : 203 billion won (27.7%)

Facility Modernization and Others

: 131 billion won (17.8%)

Description of Sewerage System

• 85% area of Seoul is served by Combined sewer system.- During rainfall, runoff and domestic sewage are collected in the same sewer

until combined water volume comes to 3times of hourly maximum sewage flow.

Sewage Sewage

Sewage + Rainfall

Overflow Chamber

3Q

Q Q

Q

Q

2Q

3Q

Intercepting

Sewer

Intercepting

Sewer

1st

Sedimentation

Grit

Chamber

Pumping

Bioreactor 2nd Sedimentation

3rd T-P

Removal

3rd T-P

Removal

Sterilization TMS

Bypass line

Bypass Occurring

First Rainfall Treatment Facility

Other days

Rainy days

Description of Sewer in Seoul

2801151,1988,70410,297

U-shape gutterOpen channelRectangularCircularTotal Length

(Km)

• Length by Function

4475751,022(10%)8,819(86%)10,297

InterceptorSanitary sewerStorm sewerTotal

Separate sewer systemCombined sewer system

Total Length

• Subsidiary Facilities

1,340918486,767206,092

Storm water overflow chamberGrit chamberStorm water inletManhole

• Length by Type

(Km)

(EA)

456(4%)

Present Status of Sewage Treatment Plants

• Capacity : 4,980,000㎥/d

- Night soil & Septic : 12,500 ㎘/d

• Sludge Treatment : 1,950 t/d

- In Site : Sludge Drying 650, Incineration 300

- Other Site (Sudokwon Landfill Area) : 1000t/d

• Process

-Before Jan, 2012 : Standard Activated Sludge

- After Jan, 2012 : MLE + Chemical Treatment

• Total Man Power : 547 Persons

Jungnang Water Reclamation Center

• Site : Chajangteo 5-gil 10, Seongdong-gu

• Area : 791,000㎡

• Construction Period : 1970 ~ 1997

• Construction Cost : USD 370 million

• Sewage Treatment Capacity : 1,590,000㎥/d

• Night Soil & Septic : 4,000㎘/d

• Sludge Drying Furnace : 300t/d

• Man Power : 133 persons

• 2015 Budget : USD 57.1 million

Nanji Water Reclamation Center

• Site : Jayu-ro 116, Goyang-si, Kyeongki-Do

• Area : 929,000㎡



• Sewage Treatment Capacity : 860,000㎥/d


• Sludge Incinerator : 150t/d

Drying Furnace : 150t/d



Tancheon Water Reclamation Center

• Site : Nambusunhwan-ro 6610, Kangnamgu

• Area : 385,000㎡



• Sewage Treatment Capacity : 900,000㎥/d

• Sludge Drying Furnace : 200t/d


(Private Sector Operation)


Seonam Water Reclamation Center

• Site : Yangcheon-gil 546, Kangseo-gu

• Area : 1,091,000㎡



• Sewage Treatment Capacity : 2,000,000㎥/d


• Sludge Incinerator : 150t/d


(Private Sector Operation)

• 2011 Budget : USD 54.3 milion

Present Status of Sewage Treatment (Average, 2015)

Food Leachate treatment

Digestion gas Generation

Operation

Total Night Soil &Septic

Others

Drying

Incineration

Solidification

Total

Sludge Treatme

nt Capacity(ton/day)

Effluent

InflowBOD

Operation

Total(㎥/day) Sewage Plant

Capacity

RemarksSeonamTancheonNanjiJungnangTotalDescription

63,92320,99645,171218,167(㎥/d)

3,268-4,1334,01011,411(㎘/day)

4000-4,5004,00012,500(㎘/day)

Reuse, Landfill, etc123121138

-140273587

125-125-250

Sugogueon Landfill, Incheon412125111292940

5493023885761,815

8.85.37.38.9＜10(㎎/ℓ)

136128146173(㎎/ℓ)

1,520,000740,000530,0001,270,0004,370,000

1,630,000900,000860,0001,590,0004,980,000

174

88,072

170-474264908(㎥/day)

Development of Sewerage Management in Seoul

Before 1960

• National Income : under USD 80/capita as GNI

• Area : 268㎢, Population : 2.4million

• Reconstruction and extending of sewers (225km) built before Korean War (1950~1953)

• No treatment plants, sewage and night soil were discharged into streams and Han River

1961 ~ 1980

• National Income : USD 82 ~ 1,645/capita as GNI

• Area : enlarged to 605㎢ in 1973 Population : 2.5 ~ 8.3million

• Construction of 5,940km sewers in newly constructed areas (840 in 60s, 5096 in 70s)

- Service rate in 1980 : 64.8% with total 6,588km sewers

• Construction of 4 septic soil sanitary disposal plants (2,930t/d) during 1972~1976

• Completion of first sewage treatment plant (Jungnang, 360,000㎥/d) in 1979

- Sewage treatment rate of 1980 : 15% of total 2,400,000㎥/d sewage

Development of Sewerage Management in Seoul

1981 ~ 2000

2001 ~ 2015

• National Income : USD 1,800 ~ 10,841 as GNI Population : ~ 10.3million

• Construction of 4 sewage treatment plants (total 5,810,000㎥/d)

and intercepting sewers (413km) during 1984 ~ 1999

• Completion of 99.8% sewage treatment service in 1998

• National Income : USD 10,159 ~ 27,000 as GNI

• Construction of sludge treatment facilities (700t/d) in 2002

• Construction of offensive odor prevention facilities and parks, sports utilities, etc

• Construction of advanced treatment facilities(2009~2012) for nutrients removal

- Activated sludge process → MLE(Modified Ludzack-Ettinger) process

• CSO(Combined Sewer Overflow) Problem

- Seoul's sewers were mostly designed to overflow the mixture of sewage and storm

water into streams at 1,140 CSO discharge points when the flow volumes become over

3 times of hourly maximum flow of sewage in rainy weather.

- The runoff conditions and volumes of sewage generation have been changed largely

in some drainage area, and these areas need bigger intercepting sewers than already

installed one.

- Combined Sewer Overflows from discharge points in these areas usually contain a

lot of pollutants and result in public health threat. This bad impact of CSOs can be

minimized by installing pollutants reduction facilities with storm water detention facilities

at discharging points and enlarging capacity of intercepting sewer in some drainage area.

- However, these measures require huge expense (about USD 360 mil) and long time

for planning and execution.

Problems of Sewerage System in Seoul

• Sewer Repair & Replacement

- 18.8% of sewers in Seoul were constructed 30 years ago and 57.9% were 20 years

ago. Many of them have problems like decrepitude, leakage from bad joint and

insufficiency of discharge capacity. The total forecast expenditure during next 10-year

period for sewer repair and replacement purpose is over USD 4.4 billion.

• Strengthening of Effluent Standards

- For the purpose of preventing water pollution, the national effluent standards have

been strengthened continuously for 20years. BOD limitation became 10mg/l in 2008

from 20mg/l. Total phosphorus concentration limitation was 8, but it has been

strengthened to 2 in 2008 and 0.5 in 2012.

- In addition, total emission volume management system of water pollutants and first

flush control will be obligated to local governments sooner or later by national

environmental laws. These obligations will enforce local governments to secure not only

additional budget but also spaces for construction.


• Civil Complaints about Sewage Treatment Plants

- Three sewage treatment plants of Seoul are located in residential areas and a lot of

households are adjacent to the plants. Another one is located in the suburb of Seoul but

several small towns are located near the plant. Therefore, since their early operation

time, there were many complaints especially about offensive odor and depreciation of

value of their properties basically.

- Seoul Metropolitan Government have achieved large improvement of odor problems

but there are still civil complaints about inconvenience.


Ⅱ. Development Plans

Sewer Reconstruction Plan

Securing Watertightness

To protect environment against contamination of soil & stream and to prevent sewer from Infiltration/Inflow

Enhancing Durability

To extend sewer lifespan To prevent safety from negligent accident

Securing Optimal Flow

Velocity

To prevent sedimentation and bad smell

Securing Discharge Capacity

To protect civil safety and property against flooding

Purpose

Sewer Reconstruction Plan

• Construction Period : 2010 ～ 2020

• Budget : USD 4,460 million

• Target : 3,705㎞ (Sewers which are decrepitude, leaky from bad joint and insufficient

of discharge capacity)

Repair and Replacement Plan

Promotion Direction

• Planning by a drainage area unit - Working lower drainage areas first

• Citizen friendly construction

- Application of trenchless technology

- Lightweight lining with temporary facility for open-cut

• Following newly strengthened standard of phosphorus

• Safely treatment of phosphorus for prevention of eutrophication


• Budget : USD 180 million

• Target : 4 Centers

• Treatment Process and Efficiency : T-P 0.3mg/l

Construction of T-P Treatment Facilities

Background

Construction Plan

Description Jung-Nang

Process

• Echojet Green Pluss

- Kolong Engineering

• Fabric Disk Filter

- Yucheon enviro co.

Nan-Ji


- Yucheon enviro co.

Seo-Nam

•Actiflo Turbo

- Veolia Water Solution

• Fablic Disk Filter- Yucheon enviro co.

Tan-Cheon

• Echojet Green Pluss

- Kolong Engineering

• Actiflo Turbo

- Veolia WaterSolution


-Yucheon enviro co.


Echo-Jet Green Pluss

Fabric Disk Filter (YDF)

Stiring and

Coagulation Air-Flotation

Air Compressor

Fine Bubble

Rapid

Coagulation

Slow

Flocculation

Fabric Disk

Filter

Inorganic

CoagulantPolymer


ACTIFLO TURBO

Rapid

CoagulationFlocculation

Inclination

Plate Settler

Hydro

CycloneMicro Sand + Sludge Return

Sludge

Micro

Sand

Polymer

Modernization Plan for Jungnang & Seonam

• What is Modernization of Sewage Treatment Plants in Seoul?

- Compacting and laying facilities in underground

- Adopting advanced technology for new facilities

- Creating parks and recreation areas on the ground

• Target Centers : Jungnang, Seonam

- Constructing Facilities by 3 stages (2009~2030)


• Modernization of Jungnang Center

- Scope of modernization : 1,130,000㎥/d (Extra 460,000㎥/day – Previously retrofitted)

- Period : 2009 ~ 2030 (20years)

- Budget : USD 853 million

[1st Stage Project (250,000 ㎥/d ]

- 2009 ~ 2016, USD 188 million

- Top of underground structures : Sports areas, Water museum, Ponds and garden


• Modernization of Seonam Center

- Scope of modernization : 1,630,000㎥/d

- Period : 2009 ~ 2030 (20years)

- Budget : USD 1,210 million

[1st Stage Project (360,000 ㎥/d)]

- 2009 ~ 2018, USD 269 million

- Top of underground structures : Water science museum, Water garden

• Prohibition of ocean dumping with the Sea Contamination Prevention Law (from Feb. 2012)

• Preparation for increase of sludge from newly adopted phosphorus treatment process

• Prevention for interregional conflict created from sludge treatment in the other city

Background

Construction Plan


• Budget : USD 64 million

• Newly constructing facilities : 1,170t/d (present 950 → 2,120t/d)

- Jungnang : 370t/d, Drying facility

- Nanji : 160t/d, Drying facility

- Seonam : 520t/d, Drying facility

- Tancheon : 120t/d, Drying facility

Sludge Treatment Facilities Expansion

Sludge Treatment Facilities Expansion

Sudokwon Landfill FacilityDrying Facility

2015 (1,816 ton/day) 2019 (1,980 ton/day)

Sudogueon

Landfill, Dry

Others

Incineration

IncinerationOthers

Dry

- Digestion gas is being used for sludge drying . - All dried sludge is sold as fuel to thermoelectric power plants.

Ⅲ. Important Promotion Affairs in the Future

Purpose

1. Creation of Covered Parks at Tancheon Center

Resident-Friendly Sewage Treatment Center

: Build up “Resident-friendly facilities ”

by changing STCs to “Parks or Eco-friendly space”

• Site area : 392,671㎡, Covered area : 109,381㎡

• Project Cost : USD 63.3 billion

• Project Period : 1999~2016

- 1st stage : 1999~2004, 10283㎡, - 2nd : 2005~2007, 15600㎡, - 3rd : 2007~2010, 49700㎡

• Facilities : Park, Forest zone, Sports areas, Children’s playground, Parking lot, etc

• Ongoing Project : 4th Stage 33,798㎡ (2013~2016, about 33 billion won)

Tancheon Center Area View


Covered park(3rd)

Covered park(2nd)

Tancheon Sewage Treatment Center

Covered park(1nd)

4th Stage

Covered Park

4th Stage

(Constructing)

2nd Stage 1st Stage

3rd Stage

2. Creation of Resident-Friendly Space around Seonam & Nanji


• Forest park and Sports facilities at Seonam center

- Created Area : 188,500㎡

- Project Cost : USD 8.1 million

- Project Period : 2008 ~ 2011.6

- Facilities : Walking Way, Forest, Tennis Courts, Park Golf, etc.

• Sports Facilities at Nanji center

- Created Area : 10,000㎡

(Football Ground, Basketball Ground, etc)

- Project Cost : 1,000 million won, 2010~2011.2

3. Further Project

• Performing Nanji Modernization Plan

- Project Cost : USD 49.3 million

- Project Period : 2016 ~ 2020

- Facilities : Walking Way, Forest, Sports Facilities, etc

Use of New & Renewable Energy

• New & Renewable Energy

- Energy that comes from resources which are continually replenished such as sunlight,

wind, tides, waves and geothermal heat

• Use of New & Renewable Energy in STCs

- Sewage Treatment Systems are basically consisted of enormous energy consumption

facilities, however, they are also have huge potentialities of new & renewable energy

from digestion-gas, sewage heat recovery, photovoltaic power generation and etc.

Year 2015 2017

Goal of Energy Self-Sufficiency Rate for STCs

• 51% • 60%

Energy Con-sumption of 4STCs

•127,315 TOE/Year (mostly Electricity)

•127,315 TOE/Year

Energy Production of 4 STCs

• 65,775 TOE/Year(digestion gas, sewage heating pump and photovoltaics)

• 76,775 TOE/Year (digestion gas increase, construction of more sewage heating pump, etc)

Goal of Energy Self-Sufficiency Rate for 4 STCs in Seoul


Photovoltaic power generation

• Construction of solar cells on the treatment tanks and grounds

- Plan : 2,000kw (2012, Jungnang 400, Nanji 100, Seonam 1,300)

→ 10,770kw (2 015, Tancheon 2,280, Jungnang 690, Seonam 6,000)

- Construction Cost : USD 46.6 million ( invested by Electricity Generation Enterprisers )

Seonam Photovoltaic Arrays(1,300kw)


• Recovery of heat from treated water

※ 5℃-Thermal energy recovery can be achieved by heat-pump installation

- Plan : 19,000TOE (2014, Tancheon 19,000) → 30,000TOE (2017, Seonam 11,000)

- Construction Cost : USD 56.5 million (invested by Private sectors)

Sewage Heat Recovery


Digestion Gas

• Increase of gasification rate and enhancement of utility value

- Plan : 210,000 ㎥/d (2015) → 260,000㎥/d(2020)

Cavitation and Ultrasonic Wave Treatment at the inlet line of sludge digester

Present Gas Usage : Digester Heating 23.3%, Sludge Dry 22%, Generation 32.5%,

Fuel for industry 7.7%, Burning 14.5%

⇒ By enhancing digestion gas values through refining and selling gas to cogeneration

enterprises, revenue over USD 4 million will be obtained annually

Creating 4 billion won revenue

95,600㎥/d

Electricity, Heat, City Gas

Seonam, Nanji, Jungnang

Seonam

4,800㎥/dFuel for 180 vehicles

Digestion Gas

20,000 Houses

Refining

Treated Water Re-use

Current: 4.8% ( 206,000 ㎡/d )

- Road Cleaning and

Cooling water

- Subway Train Washing

- Others

Future Goal: 10% of discharge

- Maintenance water

of stream

- Water for Landscape

- Cleaning water etc

Maintenance water of stream

Water for Landscape Cleaning water

The sewerage system of Seoul shall

largely contribute to safety and

comfortability of citizen, and

preserve environment of the Earth.

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