A total of 181 companies have applied to the state Department of Public Health, which checks their financial and criminal background, for permission to open medical marijuana dispensaries. Approved companies will then go to Norwell with a specific site and plan. Norwell writes a letter of recommendation for the one with the best deal, and it goes back to the DPH for a detailed review. If the company survives that, it applies for a special permit from the Norwell Zoning Board of Appeals, and goes through the standard process of public hearings. Full story for BostonGlobe.com subscribers.