Visakhapatnam: About 20 people participated in a workshop organised by India Youth for Society and Eco Peace Leadership Centre on Saturday at Gandhi Centre. Participants raised concerns about the depletion of groundwater levels in the city. Professor of Environmental Sciences, Andhra University, P.V.V Prasada Rao, said that there was a need for waste-water treatment plants. Government and public should know about the quality of the water for each purpose, he stated. G. Harsha Vardhan and Y Appala Reddy explained the purpose of the workshop. A session about e-waste/ plastic waste will be conducted on Sunday.