The National Association of Clean Water Agencies, which represents 300 wastewater agencies, says it has been hearing complaints about wipes from sewer systems big and small for about the past four years. That roughly coincides with the ramped-up marketing of the “flushable cleansing cloths” as a cleaner, fresher option than dry toilet paper alone. A trade group says wipes are a $6 billion-a-year industry, with sales of consumer wipes increasing nearly 5 percent a year since 2007 and expected to grow at a rate of 6 percent annually for the next five years. ... Manufacturers insist wipes labeled flushable aren’t...