In addition to your own personal safety, please keep the safety of others in mind when installing and servicing septic tanks, pump chambers, etc.  Help prevent the tragic situations that have occurred in the past.  Even with the many improvements made to covers, they can still be compromised in a number of ways, allowing accidental injuries and deaths to occur.  Please remember to secure covers when installing or servicing systems.  Any time an access area is opened, it should be protected to prevent accidental entry when unsupervised.  Remember it only takes a few seconds of distraction for an accident to happen.  At other times covers may be tampered with by unauthorized individuals, allowing for the most dangerous of situations, an open access with virtually no supervision.  It is a lot easier for this situation to transpire if some or all of the screws are missing from the cover simply because someone forgot them or lost them and didn’t take the time to replace them.  So please make sure that all the screws are in place before wrapping up at the job-site.  Please also inspect covers to ensure their integrity.  Over time, covers can become weakened, especially those made of materials that are prone to degradation by exposure to UV rays or extreme climate conditions.  The best prevention can be provided by a properly fitting cast iron cover, on a sturdy riser with a safety net or grating installed in the riser.  Cast iron covers are not easily removed (over 65lbs) by children even if all of the screws are missing.  Also, they are unaffected by UV rays and weather conditions that can compromise other covers.  Safety nets can be supplied that allow pumping of septic tanks while in place.  This means that the access is protected from accidental entry even when open and not supervised.  If the cover is removed for some other unauthorized reason, the safety net provides secondary protection from accidental or unauthorized entry.  Also, poorly constructed, weak risers can become distorted during or after installation, causing covers to fit poorly and creating an opportunity for an accident to occur.  The onsite waste water industry is continually changing.  More and more systems are being brought to grade to meet these changes.  This will increase the contact between people and the accesses to those systems.  If we take a conscientious approach to this situation we can help to prevent the correlating increase of accidental and sadly unfortunate injuries and deaths that can occur.