DENR says: Butuanon gradually improving

CEBU, Philippines - The state of the 23-kilometer Butuanon River in Mandaue City is gradually improving since it was declared as a Water Quality Management Area (WQMA) in 2014, according to the Department of Environment and Natural Resources.

DENR-7 spokesman Eddie Llamedo said the condition of the river is improving from the effects of development, industrialization and other human activities.

He attributed this to the strong alliance with the local government units of Cebu City and Mandaue City.

With its designation as a WQMA, the river was placed under close monitoring to ensure that its water quality complies with the standards set under Republic Act No. 9275, or the Philippine Clean Water Act of 2004 and the Environmental Management Bureau of the DENR conducted a monthly water quality monitoring of the river in 11 sampling stations.

These stations are located in Camboga-ong Bridge, Butuanon Bridge, Tingub Bridge, Greenhills Outfall, Pilit Treasure Island, Old Pilit (HJR Outfall), Canduman Bridge, Bacayan Bridge, Sta. Lucia Bridge, Binaliw II, and Candurang in Barangay Pulangbato, Cebu City.

The parameters monitored are Dissolved Oxygen (DO), Biochemical Oxygen Demand (BOD5), Total Suspended Solids (TSS), pH level and temperature.

Based on the 2015 monitoring result released by DENR yesterday, it showed that majority of the stations got an average TSS of 72 percent which is within the TSS standard of not more 60 mg/L increase. 

The average TSS for 2015 was highest so far, which is almost seven times the maximum limit for the standard of Class D rivers.

For the BOD5 concentration, Butuanon River had a 53 mg/L increase which is more than three times higher than the standard. This value is more or less the same compared to last year’s BOD which is 53.02 mg/L.

BOD5 result peaked in the first quarter with 131 mg/L BOD5, which is almost nine times higher than the Class D criteria.

The BOD5 parameter represents the easily biodegradable portion of the water pollution. Biochemical Oxygen Demand is the amount of dissolved oxygen needed by aerobic biological organisms in a body of water to break down organic material present in a given water sample at certain temperature over a specific time period.

On the other hand, the DO, as a correlating parameter of the BOD5, as well did not reach levels acceptable to DENR Class D water quality standards of 3.0 mg/L. It was only during the third quarter that the DO concentration went above the standard of 3 mg/L.

The lowest reading recorded for the first quarter was at 2.10 mg/L. EMB said this could be explained by the high temperature conditions during the first quarter.

In 2013,  monitoring by EMB showed that the river’s average biochemical oxygen demand value exceeded the standard for Class D and its average dissolved oxygen was below the standard set for such classification.

The EMB also noted that there was an increasing trend of total and fecal coliform – bacteria that indicate the presence of sewage contamination of a waterway – in all throughout the sampling stations of the river.

The water body originates in the mountain area around Metro Cebu and eventually discharges into the Mactan Channel. Its upstream is in Cebu City and was found to be densely populated and is densely degraded in terms of water quality.

The river is considered as a highly contaminated water body due to development and industrialization. Its riverbank areas downstream are also occupied by informal settlers that mainly contribute to water pollution.

In terms of the beneficial use of fresh surface waters, the Butuanon River is classified into Class D in which waters are used for agriculture, irrigation, livestock watering; and industrial water supply class among others.  (FREEMAN)