Home / Safety Health & Environmental / Standards

The environmental mitigation measures as addressed in the EIA and EMP shall be fully implemented to avoid and alleviate the Project’s impacts throughout the Construction Phase. The following relevant standards have thus been applied, based on the Lao PDR Law and the World Bank Group’s guidelines.


Emission Limit Value

The flue gas shall be treated by the Electrostatic Precipitator (ESP) and the Flue Gas Desulfurization (FGD) devices; while the stack emission from Power Plant shall meet the limit values as tabulated below: 


Parameter Averaging Period Emission Limit Value
(6% dry gas, excess oxygen content) #
Particulate Matter (PM) 24 hours 50 mg/Nm3 Ref.1
Sulfur Dioxide (SO2)* 24 hours 230 mg/Nm3 Ref.1
Nitrogen Dioxides (NOx)* 24 hours 510 mg/Nm3 Ref.1

Remarks : 

  • Ref 1 - IFC Thermal Power Plants, December 2008. Apart from SO2 which is given a range of 200-850 mg/Nm3, selection of the emission levels in the range is to be determined by EA, taking into account the Project’s sustainability and development, plus impacts and cost-benefits of the pollution control performance.  # At 0 degrees Celsius and 1 atmosphere (atm) pressure
  • Ref 2 - IFC EHS Coal Processing, April 2007



Ambient Air Quality Standard

Prior to the construction period, an air quality monitoring was conducted and indicated that the concentration of the particulate matter less than 10 microns in diameter (PM10) was higher than the World Bank’s guidelines – especially during March to April – due to forest fires and agricultural crop residue burning which, like in other countries across the ASEAN region, have created smoke haze and dust particles in the atmosphere. Therefore, the Applicable Ambient Air Quality Standard agreed in the Concession Agreement is set up as interim targets for a staged approach to achieving the recommended guidelines. The PM10 limit values have gradually been reduced from 500 µg/m3 to 300 µg/m3; while the SO2 and NO2 limit values have not changed (please see details in the table below).


Parameter Period Ambient Air Quality Limit Value
Annual Arithmetic Mean 24 hr Average 1 hr Average
Particulate Matter less than 10 µm (PM10 ) NTP (1 Mar 2010) 100 µg/m3 500 µg/m3 -
From 1st day of year 2 to last day of year 3 80 µg/m3 400 µg/m3 -
from 1st day of year 4 to last day of year 5 70 µg/m3 350 µg/m3 -
from 1st day of year 6 to end of Concession Period 70 µg/m3 300 µg/m3 -
Sulfur Dioxide (SO2)* From NTP to end of Concession Period 0.1 mg/m3 0.3 mg/m3 0.78 mg/m3
Nitrogen Dioxides (NO2)* From NTP to end of Concession Period - - 0.32 mg/m3



  • PM10 and NOs are referred to the World Bank Environment, Health & Safety Guidelines Mining & Milling-Open Pit, August 1995 
  • NTP means “Notice to Proceed”, or the commencement date of construction period



Ambient Water Quality Standard & Effluent Standard

Parameter Unit Ambient Water Quality Standard Effluent from Power Plant Effluent from Mining


5-9 6-9 6-9
Temperature oC - < 3 degrees
< 3 degrees
DO mg/l 6.0 - -
BOD5 mg/l 1.50 - 50.0
COD mg/l 5.0 - 150.0
Total Suspended Solid (TSS) mg/l - 50.0 50.0
Oil and Grease mg/l - 10.0 10.0
NO3 –N mg/l 5.0 - -
NH3 –N mg/l 0.2 - -
Sulfate mg/l 500 - -
Total Coliform Bacteria MPN/ml 5,000 - -
Fecal Coliform Bacteria MPN/ml 1,000 - -



Noise Limit Level


The noise limits shall be complied with, using any sensitive receptor installed in the potentially noise-affected ambient environment, surrounding the Project within both Hongsa and Muang Ngeun. 

  • Prior to the Commercial Operation Date, the Noise Study and Modeling has been applied as a tool to determine the Project’s “Best Noise Limits” for one-hour equivalent day (Ld) and one-hour equivalent nighttime (Ln) continuous noise level limits. Such limits shall be established by a Noise Expert, who is a consultant with expertise relevant to the Project, and agreed by MONRE
  • Noise from Blasting – The maximum level for airblast is 115 dBA. 
  • Intermittent Noise From Power Plant - Levels should not exceed 120 dB(A) at the Power Plant boundary when the steam blowing of the Power Plant pipework is carried out. 
  • From the beginning until after the Commercial Operation Date, the Company shall ensure that the 24-hour average noise from the Power Plant does not exceed 70 dB(A) at the Power Plant boundary, and that the instantaneous noise limit (other than the intermittent noise events described above) does not exceed 115dB(A) at the Power Plant boundary (the “Operating Period Limitations”).



Electric and Magnetic Fields

The design of transmission line needs to take into consideration the technique that ensures the exposure of Electric and Magnetic Fields (EMF) meets the standards defined in the table below. 


Frequency Electric Field (V/m) Magnetic Field (μT)
50 Hz 5,000 100

Reference: IFC EHS Guidelines, Electric Power Transmission and Distribution, April 30, 2007