The Mass Municipal Association is asking the state to delay implementing the new medical marijuana law, saying there's too much that needs to be done. For example, the Department of Public Health must decide what constitutes a 60-day supply of the drug, the maximum amount that can be purchased at any one time. The DPH has to register 35 dispensaries statewide and OK each of the employees. What's more, cities and towns all over the Commonwealth are scrambling to write zoning laws to regulate the pot shops. The law was supposed to take effect April 1, but the MMA wants that pushed back to July.