Plan Review


Plan Review

Plan reviews are performed on various types of projects for properties within the Central San service area. Depending on the scope of work for the project, a plan review is performed to check for compliance with Central San’s Municipal Code and Standard Specifications for Sewer Design and Construction, determine if a sewer permit is required, ensure there are no conflicts with Central San easements, ensure proper pre-treatment devices are installed, and collect any applicable sewer fees. 

For plan review you will need to submit at least one complete set of project / improvement plans. A complete set is requested to ensure all items are reviewed and to minimize the possibility of rejection by the permitting (building, engineering, etc.) agency for unreviewed sheets. This plan set is the same plan set you will be submitting to the permitting agency for permits. Please check with your local permitting agency to determine their requirements for improvement plans (items needing to be shown on plans, paper size, number of plan sets, etc.). Though we are working towards it, at this time, we do not have electronic plan review. Printed (paper) copies of plans are required.  Plan submittals cannot be submitted via email.

As a minimum Central San requires that plans be printed on paper no smaller than 11″ x 17″. If the plans are not legible or scalable, plans will be rejected, and a larger paper size will be required. If the property contains a Central San sewer easement, the easement will need to be drawn and properly labeled on the plans.  

Encroachment Verification 

Encroachment Verifications are projects that do not require a sewer work permit, have no assessment of fees, and have no conflict with a sanitary sewer line or easement. Typical plan reviews of this type can include decks, retaining walls, patio covers, pools, spas, small additions, minor interior remodels, generators and solar panels.

ADU (Accessory Dwelling Unit) 

Accessory Dwelling Units (ADU) are projects that create a new or legalize an existing accessory dwelling unit on a property. The ADU could be a detached structure or contained within an addition to a structure or within an existing structure. Fees are collected on these projects and a sewer permit may be required depending on the route of the sewer connection.  

If the ADU is attached to or within the existing house, Central San does not require a separate sewer line for the ADU. If the sewer connection cannot be made entirely within the footprint of the structure, the ADU can also connect to the house’s sewer lateral on property. If the ADU is a separate structure, the ADU sewer line cannot connect back into the existing house’s internal plumbing; it will need to connect to the house’s sewer lateral at any point on property, downstream of the main sewer cleanout for the house. If the ADU is part of an SB9 lot split, the ADU will be required to have its own, separate connection into the public sewer main. In addition to the plan review process for an ADU, a Central San sewer permit is required when any sewer work is proposed outside of a building. A Central San sewer permit is a separate permit from the ADU building permit. 


Residential are projects on residential properties that require a sewer permit and/or collection of fees and/or have an impact on sanitary sewer lines or easements. This type of project could include, but is not limited to the construction of a new single family or multi family structure. In addition to the plan review process for a residential project, any sewer work required or proposed outside of a house requires a sewer permit from Central San. A Central San sewer permit is a separate permit from the building permit. 

Tenant Improvement

Tenant Improvements are projects on non-residential properties (commercial, industrial, public, etc.). These projects can include, but are not limited to a new commercial building(s), additions to a non-residential building, remodeling of an existing suite for a new or existing tenant, ADA upgrades, exterior improvements and signage. Depending on the project, fee collection may or may not be required. Depending on the scope of work, a Central San sewer permit may or may note be required. 

Some businesses/facilities have the potential to discharge pollutants into our sanitary sewer system. The pollutants can range from fats, grease and oils to hair, chemicals, hazardous waste, micro-organisms, and substances with too high or too low ph. These plan reviews are routed to our Environmental Compliance workgroup for pre-treatment review. Pre-treatment devices such as a grease interceptor, grease trap, amalgam separator, hair trap, sand-oil separator, sumps, etc. could be required. For a list of the types of businesses/facilities requiring pre-treatment review as well as Central San’s pre-treatment requirements, please visit our Environmental Compliance webpage.  

Large Developments

Large Developments are projects occurring on a residential or non-residential property, including infill and greenfield developments that include larger commercial buildings and/or multiple residential living units. For most large developments, a pre-application meeting with Central San is strongly recommended. During the meeting, relevant Central San staff can discus with you the sewering requirements, pre-treatment requirements, and potential fees. For a pre-application meeting, please email the permit counter with the project location, brief description of the project, and a copy of the project plans. Permit counter staff may request additional information to determine which Central San staff members should attend the meeting. Meetings are held virtually and Central San will send out the meeting invite.    


Demolitions are projects where a structure is being demolished. When a structure(s) is to be demolished, if the structure(s) is connected to the sanitary sewer system, the sewer line will need to be abandoned or temporarily capped near the property or sanitary sewer easement line. A sewer permit is required to abandon or cap the sewer line. The permit will need to be pulled prior to the start of demolition. This is to protect the sewer system from construction debris and intrusion of rain and ground water. If a “demo only” plan is submitted, Central San will not stamp off on the plans until the sewer abandonment or cap permit has been pulled, the work inspected, and the permit is finaled by the Central San inspector.  

If the structure to be demolished is not connected to the sanitary sewer, such as garages and pools, Central San will still review the plans to ensure there are no conflicts with any sewer line or a sanitary sewer easement. 

If a pool or spa will be demolished, remember to get your free discharge permit. This will need to be applied for before discharging the pool water to sewer.