Experts kick up a stink over livestock wastewater treatment rules

Regulations regarding the treatment of wastewater produced by livestock were impractical and needed to be amended, according to experts and livestock producers.- Photo thanhnien.vn

Tong Xuan Chinh, vice head of the Livestock Production Department under the Agriculture and Rural Development Ministry, said that two circulars on wastewater treatment and livestock wastewater treatment had been issued by the Ministry of Natural Resources and Environment Ministry in 2015 and 2016.

According to Standard 08 and Standard 62, as they are known, livestock wastewater must be treated to meet 36 criteria before being discharged into the environment, Thanh Nien (Young People) Newspaper reported on Wednesday.

The wastewater would be “as clean as rainwater”, Chinh said, adding that the regulations were unreasonable and caused difficulties for producers.

According to Standard 62, after being treated, livestock wastewater should have a chemical oxygen demand (COD) of 100-300mg per litre and five-day biochemical oxygen demand (BOD5) of 40-100mg per litre.

COD is an indicative measure of the amount of oxygen that can be consumed by reactions in a measured solution. It is commonly expressed as mass of oxygen consumed over volume of solution.

BOD5 is a water quality parameter that measures the quantity of biodegradable organic matter contained in water. This biodegradable organic matter is evaluated using the oxygen consumed by the microorganisms involved in natural purification mechanisms.

Under Standard 08, permitted COD ranges from 10 to 50 mg per litre, and BOD5 from 4 to 25 mg.

“The limit is lower than in developed countries like the US, Japan and EU nations,” Chinh said.

Apart from major industrial livestock farms with advanced waste treatment system, the majority of farms nationwide were using biogas digesters that cannot meet the current regulations, he said.

Ngo Tien Dung, a researcher from TH Milk Group, said the group spent VND28,000 (US$1.2) to treat a cubic metre of wastewater to meet the criteria regulated in Standard 62. On average, they had to spend an extra VND11,000 ($0.5) to treat 1 cu.m of wastewater to meet Standard 08.

“Extra spending would hike production costs and the group cannot accept that,” he said.

He added that the Standard 82 and Standard 08 also prevented the company from using treated wastewater irrigate their farms.

Au Thanh Long, vice chairman of the Southeastern Mekong Delta Poultry Production Association, said that because of high standards and high costs, livestock producers were hesitant to implement the regulations, and some could be using tricks to “dodge the law”.

Tram Quoc Thang, a pig farm owner in HCM City, said that huge investment was needed to build a wastewater treatment plant through which the water would meet the criteria.

“We will not invest until other farms do,” he said.

Chinh from the Agriculture Ministry that strict regulations on livestock wastewater were hindering the use of organic fertilisers.

About 11 million tonnes of fertiliser are currently used in Việt Nam each year, 90 per cent of which are chemical-based.

“Standard 08 and Standard 62 should be amended, especially regulations on processing wastewater into liquid organic fertilisers,” he said.