Water Supply and Wastewater Disposal System Evaluation Information
This evaluation is a common part of the home sale process and is used to ensure the system is functional and meets Alaska Department of Environmental Conservation (ADEC) requirements. There is no local or state enforcement body for private wastewater systems. Inspection results are not shared with anyone without your consent and there are currently no legal consequences for systems that fail to meet requirements. The results of the inspection are for your information only.
System Registration
As of October 1, 2023, ADEC requires all on-site wastewater disposal systems to be registered (18 AAC 72.501). We will search the ADEC Electronic Data Management System (EDMS) and physical files for documentation. If none are found, we will ask if you have any. If needed, homeowners may hire a licensed Professional Engineer to submit an After-The-Fact registration to ADEC (18 AAC 72.560). We can provide our technical notes, site map, and letter report to Goldstream Engineering, Inc. to facilitate this process. The registration takes 2-3 weeks and costs $800.
If you need help using the ADEC website just give us a call! We are happy to walk you through it or if you email over the address we can do a search for you. Sometimes documents are not available online but are in the physical files at the ADEC office on University Avenue.
Separation Requirements
Horizontal Separation: During the inspection, we create a site map and measure the distance between the wastewater system components and the well. If these are not met, we will recommend that system components be relocated or a waiver from ADEC be obtained.
Minimum Separation requirments from the well:
Buried heating oil tank: 25 feet
Sewer line: 25 feet
Septic tank, lift station, leach system: 100 feet
Vertical Separation: ADEC requires a 4-foot separation between the bottom of the leach system and the seasonal high-water table to ensure adequate wastewater treatment. If the leach system is too close to the water table, the wastewater may not be adequately treated before entering the water table.
We check vertical separation by comparing the elevation of the septic tank or lift station outlet with the water level in the well. If the system does not appear to meet the 4-foot separation requirement, we will recommend that a certified installer dig a test hole near the leach field to confirm.
If the separation requirement is not met, we will recommend the existing leach field be abandoned, and a new one installed at a higher elevation, often requiring a lift station.
Adequacy Testing
ADEC assumes residential homes generate up to 150 gallons of wastewater per bedroom per day. The adequacy or “surge” testing checks if the system meets this requirement at the time of the test. We typically add 40% of the expected daily flow to the leach system for this test.
Expected Life: In Interior Alaska, septic systems have shorter lifespans due to our lower average soil temperatures. The water in the septic tank needs to be around 50°F year-round for bacteria to effectively break down waste. Cold temperatures can hinder this process, causing particulate matter to essentially clog the native soils surrounding the drainfield. Shallow bed leach fields typically last about 7-20 years, while deep trench systems can last 15-40 years, depending on location, construction, and usage.
Testing Process: We add water to the system and observe the absorption rate by periodically measuring the water level in the monitor tubes. Typically, we use an outside faucet to run water into a leach system monitor tube or the second compartment of the septic tank. If necessary, we can hire a water truck to deliver water directly into the system.
Example procedure for a 3-Bedroom Home:
- Measure water levels in each system component to ensure no immediate danger of backup.
- Measure well flow.
- Add about 180 gallons of water to the leach field, checking water levels periodically.
- Add about 50 gallons of water to the septic tank to ensure proper drainage.
- Add about 50 gallons of water to the foundation cleanout to check sewer line drainage.
- Take final measurements and determine the absorption rate.
A leach system can fail the adequacy test if the water level rises enough to back into the septic tank or does not dissipate at an adequate rate. If the leach system fails the adequacy test we will recommend having it replaced by an ADEC-certified septic system installer.
This test is intended to identify failing systems before occupants experience any problems. The testing does not damage the system, and many systems can continue being used at a reduced rate until replacement after failing the adequacy test. If a house appears to be in imminent danger of a sewage back-up, we will recommend reducing usage and replacing the leach system as soon as possible.
Septic Tanks
The septic tank traps solids and scum, preventing them from entering the leach system. It should be pumped every two years, or when there is 6 or more inches of solid buildup, to extend the life of the leach system. We will measure the solids level in the tank and recommend pumping if needed.
Septic tank capacity: ADEC has minimum septic tank size requirements:
| Bedrooms | 1-3 | 4 | 5 | 6 | 7 |
| Tank Size (gallons) | 1000 | 1250 | 1500 | 1750 | 2000 |
It is somewhat common for additional bedrooms to be added to a home after the septic system is installed. If we find the tank is undersized, we will recommend replacing it with a larger tank or adding a smaller tank to the existing one to increase capacity.
Leaking Tanks: Steel tanks will always eventually corrode and need replacement. We will compare the water level in the tank to the expected normal operating level of the tank based on size and manufacturer. If the water level is low and the tank was not recently pumped, we will recommend excavation and inspection.
Blocked Outlet: Water should flow out of the septic tank as quickly as it is added. If the drainage is slow or blocked, we will recommend excavation and repair of the discharge sewer line.
Frozen Tanks: If homes are vacant for extended periods in the winter, the effluent in the septic tank may freeze. If the tank is frozen, we will recommend having it thawed by a qualified pumping and thawing company. We advise having the septic tank pumped ahead of time if the home is going to be vacant over the winter.
Lift Stations
Lift stations move wastewater to a higher elevation, generally to meet vertical separation requirements from groundwater. These are very common in the North Pole area and in areas with shallow permafrost. We test lift stations by adding water and observing a pump-down cycle. We recommend installing a high-water alarm, if one is not present, on a separate circuit from the pump to notify homeowners if the pump fails.
Water Systems
Water Supply Flow Testing: Flow testing is conducted alongside the leach system performance test. We record the amount of water added to the leach field over time and include this information in the water supply section of our report as a water supply flow rate.
Water Testing: We are a disinterested third-party collector for water samples. Samples are analyzed by Pollen Environmental, LLC. The water system must be functional to collect samples. We cannot collect samples from winterized homes or homes without power and we cannot accept samples collected by someone else.
Regulations: Private wells are not regulated by ADEC, and there are no local or state testing requirements for contaminants. This can complicate the underwriting process with out-of-state lenders. Please confirm with your underwriter what water samples are required before testing, especially if working with an unfamiliar lender.
Common Water Samples
Total Coliform and E. Coli: If bacteria are detected, we recommend disinfecting the well or water holding tank. Homeowners can often do this themselves with provided instructions, but we do offer disinfection services if needed.
VA Loans: Often require nitrates and lead and/or arsenic testing. Confirm head of time with your lender to avoid delays at closing.
Metals Analysis: Samples for lead, arsenic, and copper have to be sent out of state for analysis, with a normal turnaround of 7-10 days.
Arsenic testing: When we collect an arsenic sample it will be analyzed for total arsenic. If a result comes back with a high level of arsenic it may be necessary to do additional analysis to determine the type of arsenic (trivalent or pentavalent) present so that the correct filtration system can be applied.
Water Filtration: Ensure your water filtration system is maintained and filters are replaced following manufacturer recommendations. Lack of maintenance can reduce filter effectiveness. We recommend replacing your filters before the inspection if the maintenance is past due. We recommend washing your hands thoroughly or wearing gloves while handling water filters to prevent contaminating the system with bacteria.
Water Holding Tank Maintenance: ADEC recommends disinfecting water holding tanks every six months. In our experience most homeowners have never disinfected their water holding tank. If you have not disinfected the tank in the last year we recommend doing so before your inspection appointment.
If you have any questions not answered here or topics you would like us to cover please let us know!
(907) 456-3854
results@goldstreamtechnical.com
We accept cash, checks, and all major credit cards!
(907) 456-3854
results@goldstreamtechnical.com
We accept cash, checks, and all major credit cards!
