Placer County updates septic rules to lower costs, make adding ADUs easier

Published Oct. 15, 2025

Homeowners in Placer County will soon find it easier and more affordable to install or upgrade septic systems, thanks to updates to the county's Local Agency Management Program (LAMP). The updated rules go into effect shortly, after approval by the Central Valley Regional Water Quality Control Board last week following earlier adoption by the county's Board of Supervisors in July.

The changes are designed to lower costs for homeowners, support the construction of accessory dwelling units (ADUs), modernize outdated requirements, simplify confusing language and align local codes with state law, while still protecting local communities. The LAMP, first approved in 2017, guides how septic systems are installed and used in Placer County and gives the county more local control than other areas in California that don't have a LAMP.

"These updates remove unnecessary barriers for homeowners while continuing to protect public health and the environment," said Jason Phillippe, director of Placer County Environmental Health.

The updated LAMP reflects new housing laws related to ADUs and addresses rising costs tied to wastewater services and sewer connections. The changes largely fall within four categories:

• Sewer connection distance: Requirement reduced from 300 feet from property line to 200 feet from structure.
• Septic repair/replacement option: Properties with septic systems needing repair or replacement may avoid sewer connection if the cost to connect is more than double the repair/replacement cost of the septic system.
• More septic installation options: Includes smaller tank sizes and allows connecting new residential structures, like ADUs, to existing septic systems if capacity exists.
• Technical updates: Includes formatting and clean-up changes.

"We all have residents in our communities that will benefit from these modifications. Construction costs have gone sky high and it's made it very challenging for people to make changes on their properties," said District 1 Supervisor and Board Chair Bonnie Gore. "This is a common-sense change to our ordinance."

The updated rules were approved by the Placer County Board of Supervisors in July and received final approval from the Central Valley Regional Water Quality Control Board on Friday. They will go into effect in the coming days.

Click here for more information about the LAMP and updated septic rules.