Would it surprise you to know that your governmental officials have a form of qualified immunity provided by something called the "Public Duty Doctrine?" Per that doctrine, if the county government owes a duty to "all" citizens, then it effectively owes a duty to "no one" -- meaning you cannot sue for damages resulting from governmental action/inaction when the government is acting in a purely governmental function, such as code enforcement. There are four narrow exceptions which are difficult and expensive to prove.
By blanketly failing to enforce the cited provisions of the septic and RV codes, Community Development has opened itself up to a lawsuit for a writ of mandamus -- a judge's order requiring them to enforce the codes. Such a lawsuit would be expensive and the plaintiffs would not recoup their legal fees. Further, because code enforcement officers have a form of "prosecutorial discretion" in which they can pick and choose when and when not to act on specific cases, the plaintiff's specific code violations would still likely go unaddressed in retaliation following issuance of a writ of mandamus. In other words, 1.) Environmental Health would still likely find that a porta potty sited uphill from a travel trailer is receiving waste water despite the surrounding clay being soaked with grey water and 2.) code enforcement would still contort themselves in order to find that a retired WSDOT trailer stamped as a "Commercial Coach" inside the door frame (per the Washington State Factory Assembled Structures Division) and with the letters "WSDOT" painted across the door is somehow an RV and not a Commercial Coach -- without even performing a site visit.
When governmental officials so obviously flaunt their duties, political change is the only viable remedy.
For those in situations which cannot wait, the law does provide a viable, though expensive, solution -- a nuisance lawsuit. Some code violations meet the criteria for such a lawsuit -- such as a neighbor whose sewage disposal methods have the potential to pollute your own well. Expect to pay tens of thousands of dollars in legal fees and be forewarned that generational trash tends to know what levers to pull to drive up your costs -- including using code enforcement's lack of action as a defense. This is not a solution for most people. But all Americans have the ability to vote.