My wife and I spent the weekend talking about gray water systems and gray water reuse when the question came up, “Is that even legal?” So today I made a series of phone calls to find out.
I regret to report: No. In Pennsylvania they are not.
Now, I can’t point to a specific piece of legislation outlawing gray water systems. No directly worded document like that exists. However, the source of this information is Martin Ferry, the Permits Chief and an environmental engineer for the the Pennsylvania Department of Environmental Protection. During the conversation he made it very clear that Pennsylvania does not distinguish between gray and black water. Both are sewage and must be processed to state standards.
PA DEP views gray water as a health hazard and no longer issues permits for residential systems involving any kind of gray water reuse. Mr. Ferry referenced DEP studies and examples of constructed wetlands for grey water reuse that did not perform as required, which ended permitting.
Another barrier to a better designed world, but now the barrier is identified, gray water reuse advocates can work within their community and with legislators to get this changed.