Oregon Department of Human Services (DHS) requires that the well water be tested for bacteria and nitrate and that the results be submitted to them. Complete information is on the DHS website. Note that the state doesn't require that these tests pass, they just require that the results be reported.
The Water Resources Department (WRD) requires that the well be tagged with a unique well identification number; get the instructions and application from the WRD website.
At this time there are no other state-wide requirements, however, your lender may have special requirements.
If you are a realtor, be sure to read through this information about privation drinking water wells published by the US EPA. What Every Realtor Should Know About Private Drinking Water Wells.
The Oregon Health Authority (OHA) and the Oregon Water Resources Department (OWRD) released an updated Well Owner’s Handbook (PDF), including health information on common contaminants, testing recommendations, additional construction setbacks for new wells, updated graphics, and more.
Some Suggestions for the Septic System
Get a copy of installation records. Contact the county office responsible for septic system permits. They should be able to provide you with a map of your property showing the septic system.
Determine the type of system. Most systems are simple gravity fed tanks connected to a network of buried pipes that allow the water to leach into the soil underground. If there is something more to the wastewater treatment system, such as pumps, filters, or special treatment methods, you need to be aware of how to maintain these and consider the associated costs.
Have the septic tank pumped! Regardless of when the tank was pumped last, start fresh.
Examine the tank. When the tank is empty, ask the pumper to look at the inlet and outlet pipes (baffles) and make sure the tank doesn't have any cracks or holes. You don't need to pay for an inspection--contrary to advertisements, there are no official criteria for septic system inspections once they have been in operation (of course if the lender wants an official inspection, you will need to satisfy that requirement.)
Know the pumping history of the tank. Generally speaking, if a septic tank has gone an extremely long time without pumping, the drainfield will be damaged. Pumping the tank does not repair the drainfield. New drainfields can cost $5,000-$10,000 or more. Consider the condition of the drainfield and cost of potential repairs.
It may be possible to go many years without pumping a septic system:
1. If great care is used to reduce the amount of water that goes through the system;
2. If steps are taken to reduce solids (like not using the garbage dispoal and wiping out grease from pans before washing);
3. If the inlet and outlet pipes are examined regularly through inspection ports and repaired as soon as they rust off;
4. And if harsh chemicals don't upset the bacterial balance.
BUT, most people aren't that careful, so periodically removing the soilds from the tank is the best way to make sure that the drainfield is not being overloaded.
Do not buy any additives for the septic system. They have not been shown to be of any benefit.
Locate the drainfield. The soil over the drainfield should be planted in grass and not compacted by activities such as parking vehicles, grazing animals, building, or intese gradening. Strips of green or brown grass are normal, whereas wetness, odors, or very lush growth may indicate a problem.
Discuss concerns with a DEQ or septic system offical in your county. This person can tell you what will be invovled if repairs are needed. They may also be able to visit the site and help located the system if there aren't records.