City: Canyon Lake, TX
Solution Type: Packaged Wastewater Treatment System
Technology Used: Advanced Extended Aeration Process
The Canyon Lake Recreation Area had an existing wastewater treatment system that was in disrepair. The site was in violation of exceeding their waste discharge permit limits into the adjacent water source, Canyon Lake. Most of the existing system was outdated and did not meet quality standards, but there were parts of the system that were recyclable and therefore could be utilized in cutting costs when installing the new system.
Using recycled equipment and tankage makes a project more challenging. Since this was a replacement of the original system at Canyon Lake and not an initial installation, RWL Water had to alter the design. This meant integrating the existing oversized flow equalization tank, chlorination building and flow metering device into the new system.
RWL Water supplied a 12,500 gallon per day Advanced Extended Aeration Wastewater Treatment System to treat the domestic waste from the site facilities. This system was designed to work with the existing flow equalization chamber to meet the effluent requirements of the location, 10 BOD5 and 15 TSS. The influent values were that of standard domestic wastewater, 250mg/l BOD5/TSS. These limits were required to be able to discharge into Canyon Lake. Since the existing flow equalization tankage was used, there was an influent pumping station that received the flow from the flow equalization chamber and pumped the influent waste stream at a controlled rate to the new secondary package wastewater treatment system and tertiary filter system, where it was treated to a degree suitable for discharge into the Lake.
This unique extended aeration system takes the influent flow from the equalization system through a pump station where the flow rate is pre-set to allow the VFD controlled pumps to pump only the desired daily average. The flow is then pumped into the new secondary wastewater treatment system to be filtered by a dual cell rapid sand tertiary filter. This tertiary filter was constructed as an integral section to the main secondary treatment system for ease of shipping and installation. The existing chlorination system was modified so that new dual, hypo-chlorination systems replaced the existing gaseous chlorination system. The feed pumps were set up to receive a signal from the existing flow meter telling how much chlorine solution to add to the existing chlorine contact chamber based on the amount of flow going through the existing effluent baffle.