In-Depth Excavation reports more ADU side sewer work in Snohomish County

In-Depth Excavation says side sewer and storm drain trenching has picked up across Snohomish County as homeowners pursue ADU permits under Ordinance 25-014 and new Washington dig rules. The shift is also being shaped by Everett lateral requirements, septic-to-sewer connections and a dry summer that has helped crews keep trench work moving. Why it matters: - Snohomish County’s ADU rule change has increased the amount of sewer proof, permitting and trenching needed before many projects can move forward. - Side sewer work now sits at the center of more ADU timelines, especially for homeowners switching from septic or tying into public sewer. - Washington’s 2026 dig law adds another gate before excavation can start, raising the coordination burden for property owners and contractors. What happened: - In-Depth Excavation, a Snohomish-based sewer excavation contractor, said side sewer and storm drain trenching across Snohomish County has increased since the county adopted Ordinance 25-014 on March 19, 2025. - The ordinance took effect March 30, 2025, expanded detached ADU allowances in urban zones and still required proof that sewer or septic capacity can handle added demand. - The contractor said homeowners and builders are calling for trenching that can be scheduled around permit submittals. - The company works from its Snohomish office at 3220 157th Ave SE. The details: - Unincorporated ADU applications through Snohomish County Planning and Development Services must include a water and sewer availability letter from the local purveyor when the lot uses public sewer. - Properties on septic need Snohomish County Health Department clearance before PDS issues a building permit. - Everett requires each accessory dwelling unit to have its own side sewer. - Everett allows connection to an existing lateral only if the shared line is at least six inches for the full run to the main. - Everett Public Works requires a side sewer permit before excavation. - Everett also requires trench shoring when cuts exceed four feet. - County utility work that crosses a county road right-of-way must go through PDS utility permits sent to SCD-Utilities@co.snohomish.wa.us. - As of Jan. 1, 2026, crews cannot start sewer excavation until all utility operators return a positive locate response through Washington 811. - Excavators must still call at least two full business days before digging and mark the work area in white. - In-Depth Excavation says it handles locates, trenching, pipe bedding, backfill and haul-off. - The contractor says recent jobs in Snohomish, Everett, Lake Stevens and Marysville have included side sewer repair and replacement, new ADU laterals, storm drain installation, catch basin work and grinder pump vaults. - The Snohomish County Health Department Savvy Septic program can fund sewer connections up to $30,000 for qualifying low-income homeowners when a failing septic system must connect to public sewer. - Side sewer work on those projects must meet the serving water or wastewater district standards. - The contractor holds Washington license DEPTHDE828N7 and carries bonding and insurance. - In-Depth Excavation says its team has more than 60 years of combined excavation experience and more than 400 completed projects across Snohomish, King and Skagit counties. - Property owners can request a free on-site estimate by phone at (425) 367-1521. - More information is available on the company’s LinkedIn page , Instagram profile and Facebook page . Between the lines: - The ADU rule change is not just a zoning story; it is also creating more utility work before construction can begin. - Everett’s separate side sewer rules and the statewide locate requirement make sewer-related scheduling more complex for projects that cross city or county lines. - Dry soil conditions have likely helped crews keep trenching on schedule, since lower rainfall reduces flooding in open cuts and can make compaction easier. - The University of Washington climate office ranked June 2025 among the ten driest Junes statewide since 1895, with Olympia, Seattle and Hoquiam also posting top-ten dry records. - Ecology said May through July 2025 was the driest such stretch on record for Washington. What’s next: - More ADU-related sewer work is likely to continue as homeowners move from permit planning to excavation and restoration. - Projects that involve septic replacement, utility crossings or Everett lateral work will keep requiring early coordination with local agencies and Washington 811. - In-Depth Excavation is steering owners toward free on-site estimates as demand for trenching remains tied to permit timelines and utility availability letters. The bottom line: - Snohomish County’s ADU expansion has turned side sewer work into a key early step, and new utility rules are making excavation more schedule-sensitive than ever.