As we are moving into full-scale implementation of sewerage and sanitation services, we are learning a lot about how to effectively deliver these types of services in a highly urbanized yet developing city. One of the main issues is basically land acquisition for STPs. It is very difficult to find an open area of land, especially for sewage treatment, in Metro Manila. Pipe-laying is also very difficult. Sewer pipes rely on gravity, which means they have to be laid at much deeper depths. Trenches should be much wider. Unlike water supply pipes that are pressurized, sewer pipes need to maximize gravity flow to reduce operational costs.
Apart from this, acquiring customer acceptance and local government support is also a key challenge in implementing sewerage projects. As such, we've endeavoured to have an effective interaction and discourse with the local governments and agencies. We've found this to be the key to almost every successful project, which we of course combine with a good information-education campaign with the surrounding residents.
From an operational perspective, another challenge is solid waste, which enters our combined systems through drainage canals. We're not actually mandated to haul and treat solid waste as part of our concession, so we have to rely on cooperation with local governments to address this issue as well. Another aspect we find difficult, which is common for all sewer systems but is even more difficult in combined sewer systems, is the variability of influent to our STPs. We have to closely monitor our processes and make sure our personnel have the best training available in order to make sure our treatment plants continue to comply with effluent standards.