The scope of the work covered design of 10 WWTPs for treating waste water from 13 towns, with the necessary external connections (collector connecting to the sewerage network, outfall to receiving waterway, water supply, power supply, access and telephony). In all cases treatment was by means of activated sludge in prolonged aeration, for population equivalents of between 1,000 and 15,000, with a total PE of 28,559.