Septic Systems (On-site Wastewater Treatment Systems)

Weld County Code: OWTS Regulations (Municode)

Setback Requirements for OWTS Installation(PDF, 20KB)

Fee Schedule(PDF, 111KB)

Septic Pump Checklist(PDF, 206KB)

Portions of the septic system are backfilled prior to the inspection, i.e. top of tank covering size stamp, pipe in stone bed covered, chambers covered, manifolds covered. For a final inspection to be completed, staff needs to be able to observe all portions of the system. Most common issue is the covering of pipe in a bed/trench.

Not enough fall on sewer line from house to tank and effluent line to distribution box. A minimum of 1/8”/ft. of fall is required. This requirement is so that the piping does not hold/store water in the pipe which could lead to freezing of the effluent in the lines in the winter time, and that in turn could damage the piping or cause a back up into the house.

Less than 5 feet of distance between the septic tank and the distribution box. Prevents backups from d-box and absorption area to septic tank.

Distribution box not installed outside of the absorption bed or trenches. The purpose of having the distribution box outside of the absorption bed or trenches is to prevent the distribution box from settling and from becoming saturated in a way that effluent isn’t dispersing to all portions of the absorption area evenly.

Solid pipe from distribution box (header lines) connected to bottom hole of chambers instead of top hole.  Effluent piping should always go into the top hole of the chambers. The doming shape of chambers is to provide void space if area becomes saturated and effluent builds up. Lack of void space if pipes in bottom of chambers.

Piping/chambers not installed level in trench or bed.  There should not be any slope in any absorption area. Slope will cause the effluent to pool in one area which means that the entire absorption area is not in use which could lead to the system failing prematurely.

Absorption field or bed system installed greater than 4 ft. of the permitted depth. From original grade to bottom of excavated area cannot be deeper than 4 feet in any area of the absorption field.

Header lines from distribution box to chambers sloped backwards towards the distribution box.  Flow of effluent should always goes towards the bed/trench.

Unequal number of chambers in each trench or row in bed. (example 15 chambers in the first row and 20 in the next).  Each row/trench should have an equal number of chambers. If there is an odd number the next row should be within 1 chamber of the other rows. (example 15 chambers in first row and 16 chambers in the second row)

Septic tank lids are not open for proper inspection of tank interior. Inspection staff needs to observe installation of piping inside the tank to ensure that it was properly installed. The lids can be placed loosely on top, but should not be completely set down (concrete lids) or screwed down (plastic riser).

Septic Cleaners

Septic Engineers

Septic Installers

Community Septic System Owner's Guide (Online Tool)

Where is my on-site wastewater treatment system located?

One way to determine the location of your on-site wastewater treatment system is to start in your basement or crawlspace and determine the direction the sewer pipe goes through the wall. Then go outside and start probing the soil with a thin metal rod 5 - 15 feet from the foundation to find the septic tank and then beyond the septic tank to find the septic absorption field. Once you have found your system, draw a map and keep it on hand to save time on future service visits. You also may contact the Health Department at (970) 304-6415 to check if there is a septic permit and inspection of the system installation on file.

How often should I have my on-site wastewater treatment system inspected?

Inspections can reveal problems before they become serious, and by checking the levels of sludge and scum in your tank, you can get a more accurate idea of how often it should be pumped. We recommend you inspect your system annually. Annual inspections help ensure your system is working properly, determine when it should be pumped, and can prevent the high cost of on-site wastewater treatment system failure.

Can I tell when the last time my on-site wastewater treatment system was pumped?

Unless you have some type of documentation available to you, it may be difficult to determine when it was last pumped. You can however "test" the system by measuring the scum and sludge layers. Contractors may push a clear plastic tube through the different layers to the bottom of the tank. When brought back up, the tube retains a sample showing a cross section of the inside of the tank.

The layers also can be measured using a long stick. To measure the scum layer using a stick, a three-inch piece of wood is attached across the end of the stick to form a "foot," and the stick is pushed down through the scum to the liquid layer. When the stick is moved up, the foot meets resistance on the bottom of the scum layer, and the contractor marks the total thickness. As a general guideline, if the scum layer is within three inches of the bottom of the inlet baffle, the tank should be pumped.

Does it help to add yeast to my on-site wastewater treatment system?

Most biological additives, such as yeast, are harmless, but some chemical additives can potentially harm the soil in the drainfield and contaminate the groundwater. There are many products on the market that claim to help on-site wastewater treatment systems work better. However, there is not a magic potion to cure an ailing system. The general consensus among OWTS experts is that additives are unnecessary and money is better spent pumping out the septic tank.

How do household cleaners affect my on-site wastewater treatment system?

Always use cleaning products as recommended by the manufacturer. Most household cleaning products will not adversely affect the operation of your septic tank. However, drain cleaners are an exception. It only takes a small amount of these products to kill bacteria and temporarily disrupt the operation of the tank. Other hazardous household products include paints, varnishes, thinners, waste oils, photographic solutions, and pesticides. These items can overtax or destroy the biological digestion taking place within your system.

How can I tell if my on-site wastewater treatment system has failed?

The signs of a failing system may include:  

•  slowly draining sinks and toilets
•  gurgling sounds in the plumbing
• plumbing backups
• sewage odors in the house or yard
• wet or mushy ground
• grass growing faster and greener in one particular area of the yard
• tests showing the presence of bacteria or nutrients in well water

The appearance of one or more of these warning signals should prompt homeowners to have their system inspected. OWTS failures also can occur without any of these warning signs.

I’m buying/selling a house in Weld County that is on an on-site wastewater treatment system. Do I need to have it inspected and/or obtain a Transfer of Title Certificate?

No. Weld County does not have a Transfer of Title Inspection or Use Permit program. You are not required to have your on-site wastewater treatment system inspected upon title transfer or obtain a use certificate.

The Weld County Department of Public Health and Environment recommends you have the on- site wastewater treatment system inspected and the septic tank cleaned and inspected by a licensed septic cleaner prior to new ownership taking place.  A list of licensed septic cleaners is located on the OWTS website main page under the Sewage Professionals tab.

CDPHE: On-site Wastewater Treatment Systems

National Small Flows Clearinghouse

EPA: Septic Systems