Septic systems aren’t the only sources of pollution that can harm commercial shellfish beds and other marine life. Manure from farm animals and wildlife, and runoff from hard surfaces such as driveways, can also contribute. The main culprit is fecal coliform, a bacteria present in human and animal waste that can contaminate shellfish beds when the waste makes its way to tidal waters.

That said, owners of rural properties served by septic systems have no cause for complaint about — nor are they being particularly singled out by — a Skagit County on-site program that requires inspection of septic systems every one to three years.

Not the least consideration is that the inspections are now required by state law, and the county is expected to fulfill that obligation.

Local shellfish beds are fragile to begin with. Excessive fecal coliform levels forced closure of commercial shellfish beds in Samish Bay twice this past spring, because contaminated shellfish can cause health problems for humans that consume them.

Any threat to the shellfish beds’ well-being undermines an important local economic activity whose vitality must be preserved. Learning where the threats originate, and doing something about it, is only sensible.

Septic systems are a necessary and workable aspect of rural life, and will continue to be. The county expects that regular inspections will help it better identify and find solutions for the pollution problem.

Some rural residents fear that they are being unfairly targeted by the inspection program. There’s no evidence of that, and in any event a thorough inspection program can only serve to reward those whose systems are well-maintained while identifying those whose are not. It is unthinkable that any septic systems could go without inspection for much longer.

The county’s health department has identified 10 potential areas of concern — all in the western part of the county, including some inland streams — that have many septic systems that have not been inspected. The department has proposed that those areas get special designation from the county.

County officials have set 2012 as the target date for completing inspections and repairs of all septic systems in five coastal “marine recovery areas that include Samish, Similk and Padilla bays, and five other “sensitive” areas that drain into coastal waters.

We encourage the county commissioners to adopt an ordinance confirming those areas of concentration at their Sept. 16 meeting. A fair but aggressive inspection program is needed now, before pollution solutions become even more difficult to identify and enforce.

• Editorials reflect the consensus opinion of the editorial board and are written by its members: Publisher L. Stedem Wood, Editor Don Nelson and City Editor Dick Clever. Signed columns reflect the authors’ viewpoints.