Contact Permit Sonoma's Project Permitting and Engineering Records requests, at 707-565-2268. The staff there can provide you the permitting requirements for connection to agency operated sanitation facilities. Their website is: http://sonomacounty.ca.gov/PRMD/Eng-and-Constr/Sanitation-Sewer/
Sonoma Water manages the system to minimize rate increases while ensuring the infrastructure will be in place to handle present and future needs. The costs of operating the treatment plant and collection system, as well as paying for repairs, maintenance, and replacement of worn out infrastructure must be paid by the users of the system.
Sonoma Water does not have a cost effective method of measuring usage since we do not directly deliver your water to you and the cost of installing meters on the sewer system is prohibitive. Sonoma Water also does not have the staffing to track the number of people per household which can change frequently. This leads to the need for a flat billing method per ESD (used by 84% of similar entities in California) which is also easy and inexpensive to administer.