Two local lawmakers are announcing a bipartisan effort today to regulate a toxic industrial chemical that has tainted the drinking water of thousands of people in Seminole County for years and possibly decades. There are no mandatory limits or other drinking water regulations for the chemical, 1,4-dioxane, whose dangers were little discussed until a series of reports in the Orlando Sentinel last year. Local authorities say the absence of regulations has left them floundering with little assistance for solutions, unsure of the need for transparency to the public and potentially saddled with hug…