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Building   Your Future  


 Nature in Mind

At Colorado's 1st Septic & Excavation we strive to assist you with your property development needs in full compliance with local land use requirements and Colorado Department of Public Health and Environment regulations.   

C1SE's Experience, Training, and Certifications enable us to provide you with services which are second to none in 

Costilla County and the San Luis Valley.  

Our designs balance your needs and vision of the property with proper installation practices to 

maximize the available space and minimize the impact to the environment. 

In order to build a home in Colorado on property which is not serviced by a local sewage treatment works, an Onsite Wastewater Treatment System  (OWTS/septic system) must first be permitted by the local public health department or its designated agent.  In the San Luis Valley this means that most people who wish to build or set a home on undeveloped property outside of the established cities, towns, and communities in the region will need to have an OWTS installed as one of their first steps, and this generally must happen before a building permit for home construction or a permit to set a manufactured home will be issued.   

Our familiarity with the San Luis Valley , and detailed knowledge of Costilla County especially, allow us to confidently take on any project.  Located in Fort Garland, 16 miles north of the oldest town in Colorado,  C1SE has a long history  of serving Costilla County residents with their OWTS and excavation needs and has completed projects in virtually every part of Costilla County .  We have also designed and installed OWTS in Alamosa and Saguache Counties and will gladly accept projects in those and other counties in the San Luis Valley  

C1SE utilizes the latest top quality products and most widely accepted techniques in OWTS installation

 to ensure that you get a low maintenance system that will last a lifetime and beyond.   

 All of our OWTS components and materials are purchased from local vendors to support small businesses and help sustain the local economy.  

We can price match in most situations, and will provide a quality of service which sets the standard for OWTS installation. 

C1SE's State certification in Site and Soil Evaluation and

National Certification in Design, Installation, and Inspection are unmatched in Costilla County  

Please contact us today so we can begin to discuss your future. 

(719) 379-6987

Si Hablamos Espa n ol


Septic System Installation

Driveways - Site Development and Improvement

Excavation - Cisterns - and more

Whether you have just purchased your property or have owned it for years and are just beginning to develop it, there are many steps you will need to take to fully enjoy it. 

Driveways and Site Development

Many parcels in the San Luis Valley are completely undeveloped and do not even have safe access to a public road.  Once the proper permit applications have been submitted to the appropriate local agencies, Colorado's 1st Septic and Excavation, LLC can begin to create an access point to the property, clear and level potential spots for development, and create paths throughout the property so you can safely maneuver vehicles, travel trailers and RVs, and materials and equipment to the necessary locations.  



C1SE can set culverts which allow run-off to pass through rather than wash out your newly created driveway.  If you desire gravel or road base, we can bring that it and spread it to create a more optimal route through your property.  Even if you already have a primitive driveway and semi-clear spot where you'd like to develop, C1SE can improve any situation which is in disrepair or in need of finishing.  We will also be happy to install gates on your new or impoved driveway. 


On-site Wastewater Treatment Systems



In order to place a home on vacant property which will someday be occupied for any period of time, you will first need to have an Onsite Wastewater Treatm​ent System installed.   Once this system is installed, you can be issued a permit to construct your new home.  Having an OWTS installed on your property will also enable you to be issued a permit to live on site in an RV or camper trailer while your home is under construction.   






















Most OWTS for single family dwellings in this region can be served by a simple gravity fed design and have only two main components outside the home. The first is the holding tank where all wastewater is sent and where it separates into various layers. Once this separation is complete, the clearest layer exits the tank and is directed to the Soil Treatment Area (STA) which is commonly known as a leach field. The required size for both of these depends primarily on the number of bedrooms that will be in the dwelling and the soil type at the STA. The number of bedrooms determines the size of the tank and the amount of estimated daily water usage by the occupants. The soil type is determined by excavating two test pits to a depth of eight (8) feet in the vicinity of the proposed STA and examining the soil beneath the surface. The ability of that soil type to effectively treat the amount of wastewater (effluent) being introduced determines the size of the STA.  Other factors such as high ground water or shallow bedrock can also affect the size and type of system required. 

Tanks must have two compartments and be approved by the CDPHE, and the minimum size is 1,000 gallons (1,250 in Costilla County).  C1SE utilizes concrete tanks whenever possible to ensure problem free, permanent intended usage with proper maintenance.  The STA generally consists of two or more separate trenches with an adequate space between each.  Plastic devices known as chambers are placed inside these trenches.  Effluent passes from the tank to the STA and remains inside these chambers until it is able to leach/percolate into the soil beneath where it slowly begins it's journey back to the aquifers from which it came.  C1SE uses Infiltrator Quick 4 Plus or Quick 4 Standard chambers in all of our installations.  

Colorado's 1st can install your system quickly and affordably.  Our designs will take in to account immediate and potential long term usage. We can install RV dumps which will be used immediately for construction or camping purposes. We can install your system in way that can serve out buildings such as garages or guest quarters. We will consider the size of the dwelling you intend to build and the possibility of adding more bedrooms.

Whenever possible, your system will be installed in a way that would allow for future expansion of the home and also the OWTS. Once completed and inspected, your OWTS will be backfilled to protect the componenets and allow the system to function properly.  The site will then be manicured to the greatest degree possible to keep your property looking clean and organized. You will also be able to locate, identify, inspect, and maintain all of your OWTS components by their above-grade indicators.  

You should never experience any problems with your new OWTS as long it is used as intended and maintained regularly.  If problems should occur as a result of an incorrect design or improper installation, we will be happy to correct the problem at no expense to you.  


Excavation and More

Once you have access to your property and your OWTS has been installed, you will likely need to have the home site further prepared and an area for a foundation excavated.  C1SE can create an adequate area for your foundation with a safe, vehicle-sized access into the excavation.  We will place the excavated soil in an area on the property where it will be out of the way of concrete trucks or other equipment which may need to be driven around the site.  This soil can then be used to backfill around the foundation or used as fill material in other areas of the property.    

Although our primary areas of service are OWTS installation and general excavation, Colorado's 1st Septic & Excavation can also provide a variety of other services as necessary.    

We can also assist you in pouring a foundation for your new home and transporting the materials necessary to do so.  We can build fence around all or a portion of your property, and we can provide a wide variety of other services that you may require during the course of your development. 

 Whether you are just starting to develop your property, are near the end, or are anywhere in between, Colorado's 1st Septic and Excavation is your go-to name for all aspects property development.  Our knowledge, expertise, and experience in OWTS and land use issues will prove invaluable to you as you embark on your journey of creation.  Our dedication to the community and the environment enables us to guide you on a course that will help ensure long lasting enjoyment of your new home.   

Please call us today to discuss your new or ongoing development. 

 We are happy to speak with you about the services we can provide and give you general rates and baseline quotes for our most popular services. 

(719) 379 - 6987

Cell: (719) 580- 7915

If you intend to have your home's fresh water needs served by a holding tank (cistern) either permanently or temporarily until a well can de drilled, C1SE can assist you in locating and placing a cistern at an appropriate depth to help prevent freezing during the cold San Luis Valley winters, and we can excavate trenches for water lines from a well or cistern to the home.   

Featured C1SE  Projects




Costilla County OWTS

Foundation Footer


Alamosa County OWTS

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