Updates of Water Environment
Governance in Japan
HASEGAWA Fumiaki
Deputy Director, Environmental Management Division
Environmental Management Bureau,
Ministry of the Environment,
30 January, 2024
The 19th Annual Meeting in Hayama, Japan1

1. Goals of water environment
Environmental Quality Standard(EQS) is an administrative goal, orregulation aimed at maintaining a desirable set of conditions.
EQSs are designed contribute to the welfare of humankind and to ensure
the healthy and cultural lifestyles of the present and future generations.

The goals are set forth in the Basic Environment Law (1993)※Replaced from Basic law for environmental pollution control (1967)◆ Environmental Quality Standard (EQS)– EQS for protection of human health– EQS for conservation of living environments
EQS is set based on the “Effect on people” and “Effects on living environment(including aquatic life)” of each public waterbody◆ Effluent Quality Standards (EffQS) are set forth in Water Pollution
Control Law since 1970
– Standards for the protection of human health– Standards for the conservation of the living environment
EffQS regulates wastewater from specified factories/establishments to achieve EQS anduniformly set in nationwide; For some specified establishes, provisional effluent
standards are applied. Prefectures may set stricter effluent standards than the national
EffQS, depending on the situation

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1. Goals of water environment
EQS Parameters for Living environment
RiversLakes

Coastal waters

pH

6.0 - 8.5

6.0 - 8.5

7.0 - 8.3

BOD

≤ 1 - 10 mg/L

--

COD-

≤ 1 - 8 mg/L

≤ 2 - 8 mg/L

SS

≤ 25 - 100 mg/L etc.

≤ 1 - 15 mg/L etc.

-DO≥ 2-7.5 mg/L

≥ 2-7.5 mg/L

≥ 2-7.5 mg/L

Bottom Layer DO-≥ 2.0-4.0 mg/L

≥ 2.0-4.0 mg/L

Escherichia colicount≤ 20 - 1,000 CFU/100 mL≤ 20 - 300 CFU/100 mL≤ 300 CFU/100 mL

N-hexane extracts--

Not detectable

Total nitrogen-≤ 0.1 - 1 mg/L

≤ 0.2 - 1 mg/L

Total phosphorous-≤ 0.005 - 0.1 mg/L

≤ 0.02 - 0.09 mg/L

≤ 0.03 mg/L

≤ 0.03 mg/L

≤ 0.01 - 0.02 mg/L

≤ 0.0006～0.002mg/L≤ 0.0006～0.002mg/L≤ 0.0007～0.001mg/L≤ 0.02～0.05mg/L≤ 0.02～0.05mg/L≤ 0.006～0.01mg/L

Total zinc
Nonyl phenol
LAS3

1. Goals of water environment
Classification of each waterbody is determined based on “intended use”.
EQS of each parameter is set based on the classification.

Image of class designation (by water use and area type)4

2. Assess the status of water environment
Prefecture (subnational government)
Formulation of water quality monitoring plan
Formulated• to coordinate with the Ministry of Land, Infrastructure and Transport andgovernment ordinance city
• to effectively conduct continuous monitoring of water quality
Reportingresults

Ministry of the Environment• Compiling nationwide WQ data
• assessing the status of the water environment• reviewing existing policies

Direction, notice,technical advice
required for the continuous
monitoring of water quality

Revising existing policies
including EQS
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3. Identify pollution sources
Examples of Officially Disclosed Data

https://water-pub.env.go.jp/water-pub/mizu-site/mizu/kousui/dataMap.asp
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3. Identify pollution sources

COD mg/L

Analysis by the prefecture (case of Lake Ksumigaura)

2020

2015

2010

2005

2000

1995

1990

1985

1980

1975

1972

EQS COD : 3mg/L

Trend of COD(Average of all water areas)
Domestic
17%

24.9 t/day

Facility・Business 2%

Small-scale
Business 7%

Domestic
19%
Facility・Business 5%

11.9 t/day

Stockraising 12%

Small-scale
Business 16%
Stockraising 13%

COD

T-N
2020FY Average of all water areas

Domestic
31%
0.89 t/day

Stockraising 3%
Small-scale
Business 31%

T-P

Facility・Business8%

4. Implement measures to address issues
To address domestic wastewater problems,
following measures were implemented/strengthened at subnational levels
Developing sewerage system

Revising the Sewerage Act by devolution of authority
to subnational government in 1999

Clarification and renovation of structural standards
for combined sewerage systems in 2003

Promoting advanced treatment system in 2005

Promoting the installation of advanced Johkasou system


Revising the Johkasou Act to prohibit old type in 2001



Enforcing proper management at night soil treatment facilities



Treating untreated domestic wastewaterat community wastewater facilities

Raising awareness and responsibility of citizens (Local ordinance)

85. Evaluating outcomes and revising policies
Statistics of domestic wastewater management

77.7%

Ratio of people covered by domestic wastewater treatment system (2000 – 2022)

95. Evaluating outcomes and revising policies
Living Environment Items

Improvement tendency as a whole,but still low achievement rate in enclosed water area (lakes and inland seas).
RiversAchievement rate (%)

Total
Inland seas

Lakes

1874
1975
1976
1977
1978
1979
1980
1981
1982
1983
1984
1985
1986
1987
1988
1989
1990
1991
1992
1993
1994
1995
1996
1997
1998
1999
2000
2001
2002
2003
2004
2005
2006
2007
2008
2009
2010
2011
2012
2013
2014
2015
2016
2017
2018
2019
2020

2020
Rivers: 98.5%
Total: 88.8%
Seas: 80.7%
Lakes: 49.7%
year

Trends in achieving EQS (BOD and COD)

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5. Evaluating outcomes and revising policies
Health Items

Environmental standard value
excess specimenrate（％）
Achievement
rate (%)

Achieved Environmental standard almost over the country.

EQS revised（1993.3）
Arsenic：0.05→0.01mg/L

The number of samples
exceeded is about thesame each year

EQS revised（1993.3）
Lead：0.1→0.01mg/L
EQS revised（2011.9）
Cadmium:0.01→0.003mg/L

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5. Evaluating outcomes and revising policies
Evaluating achievements
after implementing possible measures,
these issues still remain…

Deterioration of
aquatic ecosystemand biodiversity

Reduction of SS

Delay of water quality improvement
in enclosed waterbodies
125. Evaluating outcomes and revising policies
 Enacting “Act on Special Measures” to protect particular waterbody

Laws specially enacted
for a limited period of time / for a specific and intensive purpose Act on special measures concerning conservation of the Environmentof the Seto Inland Sea in 1973 (total pollutant load reduction)

 Act on special measures concerning conservation of Lake Water Quality in 1984

 Adapting to new methods & technologies
 Seasonal operation at sewage treatment plants
to adjust nutrient discharge to restore coastal habitats Putting more efforts to promote the conversion of old-type Johkasou
to new-type Johkasou and strengthening supports to municipalities

135. Evaluating outcomes and revising policies
Amending existing laws (revising EQS/ EffQS)
Revising WQ parameters
Adding Nonyphenol to EQS in 2012, LAS in 2013, Bottom layer DO in 2016

Hexavalent chromium compounds

Escherichia coli number

Revised EQS(effective April 2022)
0.05 mg/L ⇒ 0.02mg/L

Revised EQS(effective April 2022)••

The tolerable daily intake (TDI) was evaluated 1.1μg/kg bw/day by the Food Safety Commissionof the Cabinet Office in Japan.
The Ministry of Health, Labour and Welfare
Japan (MHLW) revised the drinking water quality
standard value from 0.05 mg/L to 0.02 mg/L orlow .

Revised EffQS
0.5mg/L ⇒ 0.2mg/L
scheduled to effective April 2024

Coliform group number⇒ Escherichia coli number••At the time of this standard establishment in1971, Coliform group number was usedbecause it was not possible to measure
Escherichia coli due to limitations in analyticaltechnology (culture technology), etc.
EQS was revised because methods formeasuring Escherichia coli are now established.

Revised EffQS
Coliform group number：
Daily mean value 3,000/cm3⇒ Escherichia coli number: 800CFU/mL
scheduled to effective April 2025

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6. Challenges and future plans
Challenges
 Raising the achievement rate of EQS in closed waterbodies
 Restoration of habitats and ecosystem services
in closed waterbodies (Lake and coast) Water quality control to improve productivity
at coastal areas
 Increase in water temperature in lakes (affecting bottom DO)
Future plansEffectively conserve healthy ecosystems
at least 30% by 2030
Conservation and utilization of a good water environmentthat also contributes to biodiversity
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Thank you for your attention

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