19th WEPA Annual Meeting & International Workshop, 2024 Japan

Implementation of TMDL in Korea
January 31, 2024
Suyoung Park, Ph. D
Watershed & Total Load Management Research Division
National Institute of Environmental Research, Incheon, Korea

Table of Contents
Ⅰ. Overview of TMDL in Korea
Ⅱ. Performance of TMDL in Korea
Ⅲ. Current issues of TMDL in Korea

Ⅰ. Overview of TMDL in Korea

Background for implementing the TMDL
 Water quality management system considering
population density in the watershed.
• The densely populated human and industrial
concentration along the downstream and midstream ofrivers poses limitations in achieving environmental
standards.

 Limitations of regulation based on WQ conc.
• The concentration-based regulation focused on existing
discharge permit standards has proven challenging incontrolling the quantitative increase in pollution loads“Requirement for an enhanced WQ management system thattakes into account both WQ conc. & Loads ”

What is a TMDL?
 Total Maximum Daily Load
• A watershed management system that establishes achievable
water quality goals at the downstream point of the watershed.
It aims to reduce pollutants within the allowable total load(allocation) range.

Improvement in WQ

Effluent
Loads

Pollution
reduction

Capacity for local
development

AllocatedLoads

Effluent Load

Start YearEnd YearWhat is a TMDL?
 Total Maximum Daily Load
Lt: pollutant load target (kg/day)
𝑳𝒕 = 𝑪𝒕 × 𝑸𝒔
Ct: water quality target (mg/L)
Qs: standard flow (m3/s)
𝑳𝟏 ≤ 𝑳𝟐
L1: effluent load (kg/day)

L2: allocated load (kg/day)
L3: load reduction target (kg/day)Implement Procedure of TMDL in Korea
Establishment of Water Quality TargetBasic Plan on TMDL Management
Allocated pollution loads by unit-watershed or
basic local government

Implementation Plan on TMDL Management
Allocated pollution loads by the kinds of sourcesof pollution and polluters

Performance by Public Sector

Performance by Private Sector

Expansion of sewage treatment facilities,
Improvement of discharge water quality etc.

Improvement of pollution prevention facilities,Improvement of discharge water quality etc.

Performance Assessment
Assessment of pollution sources, pollution load,
and reduction performance

Stage Assessment
Assessment of compliance with water quality
target and allocated pollutant load

Process for achieving consensus“Communication & collaboration
between Central & Local governments”⇒ The process may be challenging and prolonge,
yet both parties persist in reaching a consensus
Central gov.
• Decision• Decision• Approval• Review• ReviewLocal gov.

Selection of Target WQ parameters► Establishment of WQ target► Basic plan on TMDL management► Implementation plan on TMDL management► Performance assessment►• Consultation• Consultation• Establishment• Establishment, Approval• Evaluation

Process since introduction of the TMDL
3 Major river

1st Stage‘04~’10

Han riverVoluntary‘04~’12Han RiverVoluntarysystem
st1 stage

2ndstage

4th Stage‘21~’30

2nd Stage‘21~’30

1st Stage‘13~’20

3 Major river(Nakdong, Geum, and Yeongsan river)(Period) 2004~2012(Target WQ parameter) BOD

1 stage(Period) 2013~2020(Target WQ parameter) BOD, T-P2(Period) 2021~2030(Target WQ parameter) BOD, T-P

3th Stage‘16~’20

2nd Stage‘11~’15st(Period) 2004~2010(Target WQ parameter) BOD

stage(Period) 2011~2015(Target WQ parameter) BOD, T-P

3 stageth(Period) 2016~2020(Target WQ parameter) BOD, T-Pth(Period) 2021~2030(Target WQ parameter) BOD, T-Pnd4 stage

Current status of WQ goals in this stage
 Status of WQ target establishment(’21~’30)
Classification

Total

Boundary between
cities & provinces

Local government
jurisdictional areas

Total

149(5)

37(1)

112(4)

Han river49(1)1237(1)

Nakdong river

41

833

Geum river31(2)1021(2)

Yeongsan river

24(2)

7(1)

17(1)

remaining river

4-4* The numbers in parentheses represent the points within the seawater
distribution section where water quality goals have not been setCurrent status of WQ goals in this stage WQ goals on boundary between cities & provinces(’30)
Geum River(mg/L)
Watershed
BOD
T-P
Geumbon C
1.00.014
Geumbon D
1.00.019
Geumbon F
1.00.016
Yoodeung A
1.20.032
Gabcheon A
4.10.118
Geumbon G
2.20.062
Byeongcheon A
2.30.105
Miho B
4.00.089
Geumbon H
2.90.083
Geumbon K
3.00.078

Han River(mg/L)
Watershed
BOD
T-P
Hangang A
1.10.028
Hangang D
1.00.034
Seomgang B
1.70.070
Bukhan C
1.40.020Hongcheon A
1.00.020
Hangang G
1.70.039
Joongrang A
4.00.220
Tancheon A
4.00.314
Anyang A
6.20.320
Hangang I
3.80.214
Gulpo A
3.90.486
Hantan A
1.40.056

Yeongsan·Seomjin River(mg/L)
Watershed
BOD
T-P
Yeongbon A
2.40.082
Hwangryong A
2.20.060
Yeongbon C
4.60.145
Seombon C
1.40.038
Yocheon B
1.50.054
Seombon E
1.10.030

Nakdong River(mg/L)
Watershed
BOD
T-P
Nakbon A
1.40.044
Nakbon F
1.90.040
Geumho B
3.00.072
Geumho C
3.4
0.098
Nakbon G
2.60.056
Hoicheon A
1.20.038
Milyang A
1.30.031
Nakbon L
2.60.049

TMDL systems in the Unite states Background & Overview• National Pollutant Discharge Elimination System(1972)
 NPDES permit program by regulating point sources• In the early 1990s, TMDL was officially implemented.
• TMDL development required by Clean Water Act for streams
impaired by a pollutant

TMDL systems in the Unite states
 TMDL is the calculation of the maximum amount of a pollutant
that a water body can receive and still meet WQ standards, andan allocation of that amount to the pollutant’s sources.

TMDL = ∑ WLA + ∑ LA + MOS• ∑ WLA: Sum of waste load allocations (point sources) Need NPEDS permit• ∑LA: Sum of load allocations (nonpoint sources)
 No permit required• MOS: margin of safety
As of 2021, a total of 74,001 TMDL
have been approved in US.
<source: www.epa.gov>

TMDL systems in the Unite states
 TMDL process<source: ’23 National Training Workshop on WQ data, Assessment, and Plans>

TPLCS in Japan Total Pollutant Load Control & its System(TPLCS)• since 1979(COD) in enclosed 3 water areas
 All the drainage basin to the specified estuaries(20)• From 2001(5th stage), TPLS(N, P) started<source: www.env.go.jp>

TPLCS in Japan
 Scheme & methods of TPLCS<source: www.env.go.jp>

Improved WQ by TPLCS
 a clear tendency of decreasing
pollutant loads.

<source: www.env.go.jp>

Comparison of TMDL
in Korea, the Unite States, and Japan
 Similarity: Limitations of concentration based WQ management☞ Introduction of a pollutant load-oriented WQ management
 SummaryClassification

Korea

USJapanStrat year

2002
Harmony between
development andenvironmental protection

1992

1979

WQ standardattainment

WQ pollution
prevention

4 major river

Impaired Waterbody

Closed water area
- Tokyo bay, Ise bay,
The Seto inland sea

Target parameter

BOD, T-P

Parameters exceeding
WQ standards such as
metals, pathogens,Nutrients, DO, etc

COD, TN, T-P

Entity in charge offormulating pollution
load reduction plans

Local governmentState government

Local government

Objective

Target region

Ⅱ. Performance of TMDL in Korea

WQ attainment rate of 3 th stage
 As of the year 2020*, the attainment rate for water quality targets
at the designated locations is 77% for BOD and 69% for T-P
Targetparameter

BOD

T-P

Target area
NonAttainment
attinment
RateWatersystem

Total

Attainment

Han

26

19

773.1%-Nakdong

41

36

587.8%

75.6%

Geum

30

16

1453.3%

86.7%

Yeongsan·Seomjin

22

20

2

90.9%

90.5%

Total

119

91

28

76.5%

82.6%

Han

26

17965.4%-Nakdong

41

30

1173.2%

97.6%

Geum

30

191163.3%

87.5%

Yeongsan·Seomjin22

16672.7%

81.0%119823768.9%

91.4%

Attainment rate inprevious stage

In 2020, the three major rivers marked the conclusion of the third stage, while the Han River
concluded only the first stage.

Improvement of Water quality
 Hangang F (Han river) Nakbon K (Nakdong river)Improvement of Water quality
 Geumbon K (Geum river) Yeongbon C (Yeongsan river)Decrease of discharge load
 According to the stage assessment, there is a decreasing
trend in pollutant discharge loads across watersheds(kg/day)Targetparameter

BODT-P

Water system

Before 20042010

20152020Han--

152,336

84,827

Nakdong

176,080

105,71168,94464,747Geum126,163

74,272

T-P (kg/day)
55,07453,568

Yeongsan·Seomjin

51,10533,33931,14030,653

Total

353,348

213,322

307,494

233,795

Han--

19,296

5,762

Nakdong-

11,121

6,147

4,346

Geum-

1,360

956

530

Yeongsan·Seomjin

-

3,933

1,849

2,181

Total

-

16,41428,24812,819

Ⅲ. Current issues of TMDL in Korea

Recent criticisms regarding TMDL Planning and evaluation based on overly complex formulas• Approximately 200 formulas are used in the pollutant
load calculation process (source → generated load →discharge load) A Reduction plan concentrated on point sources• Establishment of allocation and reduction plans focusing
on easily manageable public wastewater treatment plants​

 Lack of incentives vs. Absence of substantial restriction• No rewards for areas that have achieved target waterquality; no sanctions for areas that have not met thetarget

Efforts to improve the TMDL (Future initiative)
 Simplification of TMDL implementation• Complex equations alone may not be sufficient to calculate
everything that occurs in actual watershed. ⇒ Planningand rapid evaluation based on the latest monitoring data
through pilot projects.

 Expansion of recognized reduction activities• Expansion of the recognized scope of reduction efforts for
nonpoint source pollution through activities such as
agricultural BMPs and canal cleaning, rather than relying
on facilities like wastewater treatment plants

Thank you foryour attentive listening!

psuyoung@korea.kr