Septic System Engineering Design

Tim Johnston, Registered Civil Engineer with Acorn Onsite, Inc.

Tim Johnston, P. E. is the Civil Engineer on staff that has a lifetime of experience working with septic systems. Tim has worked through residential septic system projects, large scale commercial facility onsite wastewater treatment system projects, and everything in between. Acorn Onsite, Inc. has the long term solution as the focus of our efforts. We are experienced with and have positive working relationships with the regulators, both at the County Environmental Health Agency level and at the California Regional Water Quality Control Board levels. We are competent working through all the appropriate wastewater permitting processes. We can perform all tasks in house or we are happy to work with other consultants, professionals, architects, engineers, contractors, installers, surveyors, etc. as appropriate. 

A percolation test being conducted in Castro Valley, California.
A percolation test being conducted in Castro Valley, California.

Field Studies

Soil investigation including: soil profiles, percolation testing, topographic surveying, mapping, groundwater determination, wet weather testing, soil observation and analysis; septic engineering in Livermore

OWTS Design

Onsite Wastewater Treatment System (septic system) engineering designs. We utilize a cost effective, appropriate septic system design for your parcel. Either if it is for residential, commercial, winery, industrial use.


Septic Permitting


We are experienced working through OWTS permitting process of the various county Environmental Health Departments and the Regional Water Board, as applicable. 


System Evaluation

If you have an existing septic system that is giving you some trouble, give us a call and we can asses the options. Maybe it's a simple fix or maybe something more complicated. We are always interested in the long term solution to problems. 


Acorn Onsite, Inc. staff is committed to providing long term onsite wastewater treatment system solutions. We care for the envionrnment and we care for the customer's needs.


Real Estate Inspections and Property Opinions

We can provide honest opinion regarding the conditions of an existing septic system, regarding the feasibility of a new or replacement septic system, or any opinion related to the site's wastewater issues or concerns.

Onsite Wastewater Treatment System Engineering Design - Acorn Onsite, Inc.

We prepare an appropriate septic system design for the site. We work on residential dwellings, commercial facilities, institutional facilities, wineries, industrial warehouse, and anywhere in between. We work in Alameda County, Stanislaus County, Santa Clara County, San Mateo County, Monterey County, San Benito County, Marin County, Solano County, Napa County, Yolo County, Contra Costa County, Sacramento County, and all counties throughout Northern California and Central California. We are experienced working through any county or State permitting processes.  


Find Out the Locations we Serve

A Few Types of Septic Systems we Design

Robotic total station being used for septic topo map preparation in Fremont, California.

Conventional Gravity (Standard System)

When site and soil conditions are favorable for a simple, gravity flow leach field we find this type appropriate. As conditions, such as soil type and compact spaces, get "worse" or less favorable, more systems with more technology are useful to allow development.

Shallow Trench Pressure Distribution

On sites where shallow soils are found often a shallow trench pressure distribution system is appropriate. These systems utilize a pump or siphon to use the shallow soils to disperse and treat the septic tank effluent.

Drip Dispersal

In shallow soils, shallow groundwater, or where a pretreatment unit is necessary, drip dispersal is sometimes an appropriate technique. 

At-grade Bed Dispersal

In shallow soils, underlain by shallow rock, hard soils, high groundwater levels, etc. an at-grade bed dispersal system may be appropriate for the site.

Pretreatment Units

If site conditions or permit requirements necessitate further treatment than the depth of soil allows at the site, a pretreatment unit can be used to mitigate the concerns and allow for development.

Experimental Systems

Have you heard of a type of septic system not listed here? Give us a call to discuss that system's type as applicable to a practical application. We are familiar with many up and coming solutions and are always looking for opportunities to put these into use.

The type of septic system that is designed is based on the site and soil conditions encountered in site specific evaluation, soil testing, topography measurement, site layout, and other site development activities. Give us a call to discuss your site and see how we can help you on your next development. Check out some representative projects.

925-447-5200 or 800-832-7711

Types of Investigation

Site Reconnaissance - Initial Surface Condition Observation

A visual walk through of the site's apparent surface conditions provides useful information. Depending upon the site layout, slope, surface soil types, vegetation, and other features present that indicate some tell tale signs of OWTS feasibility and placement. 

Soil Profile

A soil profile is used to classify the soil in the potential leach field area. Often a backhoe or excavator is used to dig about 10 to 12 feet deep and classify the soil characteristics. Depth to a limiting condition such as groundwater are also observed. Soil profiles are a key aspect of designing a septic system leach field.

Percolation Testing

Often called perc tests, percolation testing is used to determine a rate water percolates into the soil. The percolation rate is then correlated to the long term acceptance rate of the soil. This is a step that is often required by county agencies, but we feel other techniques are more beneficial.

Wet Weather Testing

In some soil types and applications it is appropriate to determine how the soil behaves in the wet season of the year. Groundwater monitoring and other testing is sometimes used at this stage. We are competent working through the clays that often apply to wet weather testing.

Location Experience

We have vast knowledge on sites that we have developed septic systems on. We use our past knowledge of the area to assist in the feasibility determination. We have worked throughout the wide region of Northern California and Central California for decades. 

Published Reference Review

We do not shy away from reading. We keep current on the up and coming new in the industry, the local area, and all aspects of septic systems. This current knowledge leads to a successful project implementation. 

925-447-5200 or 800-832-7711

We can assist on your septic system projects throughout northern California and central California. Call today and speak with an engineer regarding the septic system feasibility for your next project or your need for a replacement septic system.