Estimation of non-point source BOD loading in urban area: A case study in Phetchaburi Municipality, Thailand

Main Article Content

Luepol Punnakanta
Wimon Sonchaem


The purpose of this study was to develop the equation for the BOD loading estimation from the nonpoint source wastewater in an urban area. Phetchaburi Municipality area was used as a case study. Here, the nonpoint source wastewater areas can be classified into two groups according to their land uses and runoff coefficients. One is the construction building areas having a runoff coefficient in the range of 0.50-0.90 such as commercial areas, government offices and roads. The other is the natural and agricultural areas having runoff coefficient in the range of 0.03-0.30 such as rice paddies, mixed orchards, forests, marshes and swamps. The amount of storm water passing through each of these non-point sources was the independent variable. X1 was the amount of storm water from construction and buildings areas and X2 was that from the natural and agricultural areas. The average of BOD loading during the dry season used to calculate the BOD loading from the noin-point source wastewater was 208.29 kg/day with the standard deviation at 57.89 kg/day. It was also found that the BOD loading from the non-point source wastewater (Y) and the storm water that flows through the first and the second groups were significantly related. By using the weighted least squares method, the equation was gif.latex?\hat{ํY}= 0.794X1 - 25.455X2. The coefficient of determination was 36.2% and the sum of squared error was 156.78.


Download data is not yet available.

Article Details

How to Cite
Punnakanta, L., & Sonchaem, W. (2018). Estimation of non-point source BOD loading in urban area: A case study in Phetchaburi Municipality, Thailand. Science, Engineering and Health Studies, 12(1), 59–68.
Research Articles


Daily rainfall data of Phetchaburi Municipality in 2007-2012 [Data file]. The Meteorological Department, Phetchaburi. [in Thai]

Data of wastewater pumping rate per day in 2007-2012. [Data file]. Department of Water Quality Management, Phetchaburi Municipality, Phetchaburi. [in Thai]

Panswad, T. (2006). Design manual for sewerage system. The Engineering Institute of Thailand under the His Majesty the King’s Patronage, Bangkok. [in Thai]

Pantumsinchai, P. (1995). Operating manual for control of municipal wastewater in preparation of operating manual of wastewater treatment system and implementation of effluent standards from buildings, Vol. 3 (revised edition). Roenkaew Press, Bangkok.

Pollution Control Department. (2008). The potential assessment project on pollution capacity for Chao Phaya river (Final report). Pollution Control, Bangkok. [in Thai]

Sirianuntapiboon, S. (2006). Wastewater treatment design: selection, design, control, and problem solving. Tops, Bangkok.

Theppitak, S. (2000). Sludge accumulation In wastewater collection system and wastewater treatment system, Phetchaburi province. (Master’s thesis). Kasetsart University, Faculty of Environment.

Tulyasathien, S., Wongsawan, K., & Wongsawan, S. (2001). Environmental pollution (Thai social problems). Ruamsarn Press, Bangkok.