When Title 5 went into effect and many more answers to your questions:
http://www.mass.gov/dep/about/organization/aboutbrp.htm#aboutt5



State Help ... Septic and Sewer Answers
http://www.mass.gov/?pageID=mg2subtopic&L=4&L0=Home&L1=Resident&L2=Environment&L3=Septic+&+Sewer+Issues&sid=massgov2