Installing new tanks

The newer tanks are different from the ones back in the 1970’s, not only are they made better but their portholes are easily accessible. Septic tanks that were put in around 1960 or below are usually homemade, made out of self poured concrete or stone, 1960 to about the 1980’s they have four large concrete lids that go across them. 1980 to 2000 they have either round or square porthole two of them one on each side of the tank! 2000 to now that have the plastic screw lids and are much easier to access and clean