Septic System Installation

Complete Septic Installation Services You Can Trust

Building a new home or replacing an old septic system? Turn to the professionals at Dirtworks Northwest for reliable, code-compliant septic system installation in Bonney Lake, WA, and surrounding areas in Pierce, King, and Thurston Counties.

If you're looking for a licensed excavation contractor who gets the job done safely, efficiently, and up to code, Dirtworks Northwest is your go-to team.

Full-Service Septic System Installation

We handle every phase of the installation process, whether you’re building on raw land or replacing a failed system. Our team works closely with septic designers, engineers, and health departments to ensure your project meets all county requirements.

New Septic System Installation

Building a new home on undeveloped land? We excavate and install complete conventional or alternative septic systems based on your approved design, soil conditions, and property layout.

Septic System Replacement

Is your old septic system failing? We’ll remove the existing components, excavate for the new tank and drain field, and install a modern, efficient replacement system.

Drain Field & Trench Excavation

We dig precision trenches and layout drain fields according to approved plans, ensuring proper slope, spacing, and filtration.

Septic Tank Installation

From fiberglass to concrete tanks, we provide expert excavation and setting for tanks of all sizes—along with secure backfilling and site cleanup.

Types of Septic Systems We Install

We work with licensed designers and local counties to install systems that match your property’s size, soil, and use.

• ✔ Gravity Systems

• ✔ Pressure Distribution Systems

• ✔ Mound Systems

• ✔ Sand Filter Systems

• ✔ Glendon BioFilter Systems

• ✔ Pump-to-Gravity Systems

• ✔ Advanced Treatment Units (ATUs)

Whether your lot has great percolation or challenging terrain, we’ll install a septic system that functions efficiently for years to come.

Why Choose Dirtworks Northwest for Septic Installation?

We’re not just another dirt-moving company. We understand that septic installation is a precise, regulated process that demands expertise, timing, and attention to detail.

Local Septic Installation Experts

We live and work in Bonney Lake and know the septic requirements for Pierce, King, and Thurston counties. We work directly with local health departments to ensure full compliance.

Licensed & Insured

Dirtworks Northwest is fully licensed and insured, giving you peace of mind knowing your septic project is in professional hands.

Experienced Excavation Crew

With years of residential excavation experience, we understand how to dig safely, slope trenches properly, and protect your investment.

Transparent Pricing & Timely Work

We provide clear, competitive quotes and stick to our timelines. No surprises—just dependable service from start to finish.

Our Septic Installation Process

We follow a proven process to ensure your septic system is installed correctly, efficiently, and according to code.

1. Site Evaluation & Septic Design

A licensed septic designer evaluates your property, tests the soil, and develops an approved septic plan. We can recommend trusted designers if needed.

2. Permitting & Scheduling

We help coordinate with the local health department to ensure all necessary permits are approved before work begins.

3. Excavation & Installation

Our team excavates for the tank, trench lines, and drain field. We install the tank, pipes, pump (if needed), and other system components as specified.

4. Backfill, Grading & Cleanup

Once inspected, we backfill the system and grade the site to promote proper drainage and prevent settling.

5. Final Inspection & Commissioning

We coordinate final inspection with the county and ensure everything passes before your system is put into service.

Who We Serve

Homeowners & Owner-Builders

Installing a septic system as part of a new home build? We’ll guide you through the process and make it easy to understand.

Custom Home Builders

We’re a trusted partner for local builders and general contractors. Our team keeps projects on schedule and compliant with septic regulations.

Landowners & Rural Property Developers

Need septic systems for multiple lots or a small subdivision? We provide scalable septic excavation and installation services to match your project size.

Service Areas

We install septic systems throughout:

• Bonney Lake

• Orting

• Buckley

• Enumclaw

• Sumner

• South Hill

• Graham

• Puyallup

• Spanaway

• Auburn

• Eatonville

• Tacoma

• Pierce County

• King County

• Thurston County

If you’re building or upgrading in the South Sound area, we’re ready to dig.

Frequently Asked Questions

How much does septic installation cost?
Septic system installation costs vary based on site conditions, system type, soil, and access. We provide detailed, no-obligation estimates after reviewing your site and approved design.

Do I need permits to install a septic system?
Yes. All septic systems in Washington State require county health department approval and permits. We help coordinate inspections and ensure compliance.

How long does septic installation take?
Most residential septic installations take 2–5 days once permits are in hand and the site is ready. Timing may vary based on weather and soil conditions.

Can you help with septic design?
We don’t provide engineering or design in-house, but we work closely with trusted local designers and can refer you to professionals who know the permitting and soil requirements.

What kind of maintenance does a septic system need?
Most systems should be pumped every 3–5 years. Keeping your drain field clear and minimizing water usage helps prevent problems and extend the life of your system.