More from this series:

• 3M chemical found in nine more metro lakes
  Stormwater runoff could be behind the elevated levels of PFOS; 11 other lakes studied showed little or no trace of it.
• Chemical used by 3M found in fish; advisory issued
  A chemical once manufactured by 3M has shown up in fish from several east metro lakes, prompting the Minnesota Department of Health to warn people to limit the fish they eat from those waters.
• 3M pollution case: Confidentiality breach is costly for plaintiff's lawyers
  The inadvertent release of 3M documents to regulators and a reporter brings an $86,894 penalty against lawyers.
• Innovation & accountability
  
• Judge denies class-action status in water pollution suit against 3M
  Including almost 68,000 east-metro residents would create "astounding" logistics problems.
• Lawmakers push for fast action on 3M chemicals
  The state Senate voted 60-3 to strengthen guidelines for 3M chemicals. The move follows an advisory about Minneapolis fish.
• March 14, 2007: Two 3M chemicals hazardous, state says
  The MPCA action gives it more legal leverage to clean up chemicals that were dumped in Washington County years ago.
• March 26, 2007: Lawyers hope to turn suit against 3M into class action
  A ruling on what comes next could turn the water dispute into one of the larger environmental cases in state history.
• Oct. 8, 2006: Chemical dump thought clean still a hazard
  3M-produced fluorochemicals have contaminated household wells in the city of Lake Elmo.
• Jan. 20, 2007: Chemical from 3M taints wells
  Health officials found low levels of a substance in wells in Woodbury and five other cities.
• Jan. 28, 2007: Concerns deepen over 3M chemicals in groundwater
  With the safety of drinking water questioned in the east metro, officials are trying to determine the scope of the pollution.
• Feb. 1, 2007: Rosemount, Inver Grove wells free of chemical
  
• Feb. 3, 2007: Water probe focuses on Woodbury site
  3M has 30 days to respond to the state's request for more information on how a chemical was disposed of at a former dump.
• March 2, 2007: Health fears heightened for 3M chemicals in water
  Officials have revised the recommended maximum levels, saying the chemicals found in water supplies may be more dangerous than thought.
• Feb. 28, 2007: Former DFL leader Roger Moe takes 3M lobbying job
  
• Feb. 25, 2007: Tap water worries rising
  As more residents across the east metro area buy bottled water, they're watching as an inquiry into 3M chemicals unfolds.
• Feb. 23, 2007: Bills would flag risks of old 3M chemicals
  A legislator from Cottage Grove introduced bills to respond to groundwater contamination in the east metro area.
• Feb. 13, 2007: Wary residents want answers on 3M groundwater pollution
  Citizens in the east metro area attending a meeting in Cottage Grove wanted to know about the dangers and what is being done.
• Feb. 12, 2007: Water probe's progress at issue
  A legislator called the MPCA's work on groundwater tainted by 3M chemicals "outrageous" and demanded faster action.
• March 7, 2007: 3M duo quizzed on water concerns
  Executives met with legislators in a hearing over concerns about chemicals found in private, public wells in the east metro region.
• March 5, 2007: Should you drink the tap water?
  It's been several weeks since chemicals linked to 3M have been found in the water of some east metro communities, and residents still don't have a clear answer.
• March 27, 2007: Is suit '3M-bashing' or result of company's hiding facts?
  3M's conduct and liability for east metro groundwater pollution were debated before judge, packed courtroom.