After three decades of debate and polarizing politics, the piping for the sewer Los Osos is almost all in. The 45 miles of pipeline that will serve more than 12,000 residents is about 80 percent complete. The last of the pipe should be laid by July. Construction of the sewer treatment plant bill begin in March. When completed, the plant will be able to handle about 1.2 million gallons of sewage a day. The cost of the project is estimated at just over 183 million dollars.