The impact of waterfront development towards water quality of Sungai Danga

Abstract

Waterfront developments along Sungai Danga have caused negative impacts on society and natural environmental due to the lower water quality affecting the aquatic life and destruction of habitat as an indirect result of developments and soil erosion caused. The study area has experienced development since 1990’s which mostly involving industrial and housing development. This research analyzed the current level water quality of Sungai Danga based on the Water Quality Index (WQI) and the Malaysian Interim National Water Quality Standard (INWQS). Water samples were collected from nine sampling stations along the river and analyzed to study the impact of current waterfront development. The methodology included analysis of secondary data, site visits and interview sessions with local communities as well as water samples to analyze the water quality. The respondents included developers, officers from the Department of Environment (DOE) and Majlis Perbandaran Johor Bahru Tengah (MPJBT). Water quality parameters analyzed included dissolved oxygen (DO), biochemical oxygen demand (BOD), chemical oxygen demand (COD), suspended solids (SS), ammoniacal nitrogen (NH3-N), alkalinity and acidity (pH), chromium (Cr), copper (Cu), nitrate (NO3) and nitrite (NO2) according to Standard Method 2002 and Hach DR5000. The stations were along Sungai Danga while the water samples were taken three times by taking into account the low tide and high tide. As a result, Sungai Danga water quality for year 2013 was much more polluted compared to previous year based on the results of WQI and INWQS obtained. According to WQI analysis, the water quality of Sungai Danga during low tide is much polluted than high tide. Water samples taken from all stations along Sungai Danga during low tide were found to be classified as Class IV. However, the water was cleaner at certain stations during high tide and classified as Class III. Based on comparison to INWQS, most parameters involved were categorized in Class V and IV such as COD, AN and heavy metals parameters which is Cr and Cu. Based on result gained from the interview sessions, most of the respondents agreed that depleting water quality was caused by the waterfront development along Sungai Danga. The results indicated that environmental monitoring should be further enforced in order to prevent and reduce the potential water quality impacts during construction, excavation and filling stage.