Where existing water supplies are available, the developer shall extend the existing system to serve the new subdivision and provide for lines for the extension of the system beyond the subdivision. Where existing water supplies are not available, the developer may install a complete water system to serve his subdivision and dedicate such system to the City for operation, or he may leave it to the purchaser of each lot to provide water from wells. In the event that new wells are required (either public or private), their location and the construction of all required water facilities shall conform to TCEQ rules and current city ordinances (including sanitary control easements and verification of groundwater supplies). In no event shall individual lot wells be drilled closer than 150' to any portion of a sewer or septic system or any other contamination source.