Size it yourself, or just ask. Both run on the same verified engine, locked to Lowridge's approved design manuals — so the number you get is the number you submit.
Size any OSCAR system to scale in seconds — coils, zones, basal area, sand, and a drawing, every number traced straight to the approved design manuals. The same engine designers submit with and regulators check against.
Open the Calculator →
Your on-call OSCAR expert. Ask anything in plain English — products, sizing, code, install — and get a straight answer from Lowridge's own manuals, with the sources cited. Answers in seconds, any time.
Ask OSCAR →One shared engine — the number you size and the answer you get stay locked to the same source of truth.
Onsite wastewater treatment and dispersal in the industry's smallest footprint — meeting the highest treatment standard required by code, with no disinfection accessories. Serving Washington, Oregon, Idaho and Arizona.
Ask OSCAR, the Calculator, drawings, manuals and wiring resources are organized from Lowridge's approved source library so designers, installers and regulators can check the same materials.
Open Manuals & Drawings →OSCAR-XO2, OSCAR-II and OSCAR-III materials are loaded with current Washington manuals and drawings.
View WA library →Idaho OSCAR-XO2 and OSCAR-II manuals, PE manual path and state drawings are grouped for review.
View ID library →Arizona XO2 design materials include the state design manual, O&M manual and Product Performance Listing.
View AZ library →Oregon projects are handled directly through Lowridge with state-specific design support.
View OR resources →Wastewater disperses through coils on contour over a shallow sand bed — meeting the highest treatment standard in code, then returning clean water to the ground. The least soil, the smallest footprint, no disinfection.
Lowridge provides the onsite wastewater industry with the products that protect and conserve our water resources — complete system packages that make installation quick and simple, with easy-to-follow instructions.
Our primary product has daily design flows ranging from 240 gpd to 100,000 gpd, the industry's smallest footprint, requires the least amount of soil, and is capable of meeting the highest recognized treatment standard required by code — without any disinfection accessories.
Coil-based treatment and dispersal families sized to the governing state loading-rate code. OSCAR-III remains a single-family residential path only, using the same coil-on-contour footprint approach with a lower loading rate per coil.
View manuals ↗Single-family residential design flow can exceed 480 gpd and may go up to 1,500 gpd when supported by the residential design path. Multifamily is commercial and should use XO2-15/XO2-35 kit tables, headworks, piping and multi-zone drawings from the approved XO2 design manuals.
View source library ↗Legacy low-flow questions are handled only as retrofit-to-XO2 guidance. Current product selection and sizing should use OSCAR-XO2 and the approved state manuals.
View retrofit materials ↗
Every OSCAR-XO2 kit includes a pre-assembled headworks box — flow meter, disc filter, pressure gauges, and solenoid zone valves, all plumbed and tested before it leaves Lowridge. No field assembly and no guesswork.
It is the mission of Lowridge to offer the most efficient products and methods of wastewater treatment — to protect our environment and to ensure the future of our water supply.
“Sustainability begins with economic viability. It ends with no negative environmental impacts. Lowridge products do both.”
A factual starting point for designers evaluating difficult lots. Final selection, code compliance and permitting remain project-specific.
| Question | OSCAR-XO2 | Mound / conventional dispersal | Other advanced treatment + drip |
|---|---|---|---|
| Footprint | Designed for the industry's smallest footprint. | Typically requires a larger constructed area. | Varies by treatment unit, soil and loading rate. |
| Limited soil sites | Built for shallow soil, high water table and tight setback projects in approved states. | Can be limited by vertical separation, area and slope constraints. | Can work on difficult sites, but configuration is design-specific. |
| Disinfection accessories | No UV/chlorine disinfection accessories in the standard approved OSCAR-XO2 path. | Depends on the local code path and treatment approach. | Depends on treatment standard, listing and local approval. |
| Headworks | Pre-assembled reverse-flush headworks, tested before shipment. | Commonly field-built or assembled from separate components. | Often design-specific, with multiple supplier components. |
| Design support | Calculator, drawings, manuals and Ask OSCAR use the same source-library rules. | Designer assembles sizing from code, site constraints and drawings. | Supplier manuals and local design requirements must be reconciled. |
Real OSCAR installations across the Northwest — before-and-after proof of how the system blends into a finished property.
Finished landscapeBelow-grade OSCAR field, planted and invisible
Installed systemCompact treatment and dispersal footprint
After plantingWorking drainfield beneath a usable lawn area
Coils on contourPlaced over prepared sand before cover
View the full gallery →
Field installReal installation photos, not stock imagery
“Sustainability begins with economic viability — and ends with no negative environmental impact.”
The mission of Lowridge Onsite TechnologiesTap your state for approved products, manuals & drawings, distributors and certified professionals.
Choose your state to see approved products, manuals & drawings, distributors, certified professionals and training.
Some lots could only be developed because of an OSCAR system.
240 to 100,000 GPD · the industry's smallest footprintThese are the questions Ask OSCAR is built to handle first. The full FAQ can grow from verified Ask OSCAR logs once Dave approves the next batch of public answers.
Ask OSCAR is designed to answer from Lowridge-approved manuals, drawings, product sheets, wiring diagrams and state resource pages loaded into the OSCAR source library. It does not use social media or general web claims as OSCAR authority.
Start in the OSCAR Calculator. It produces preliminary coils, zones, basal area, sand quantity, hydraulics and drawings from the same source-library rules used by Ask OSCAR.
Use Manuals & Drawings and pick the project state. Standard drawing sheets, wiring diagrams, headworks files and editable CAD downloads are grouped there when available.
Homeowner use is self-service. Homeowners should use Ask OSCAR, the calculator, public resources and certified professionals for the project path. Direct project support is intended for designers, regulators, distributors and project teams.
OSCAR tools provide preliminary guidance from approved source material. Final selection, design, permitting and code compliance remain with the licensed professional and the authority having jurisdiction.
Start with Ask OSCAR — most questions are answered in seconds. A rep only steps in when you're ready, so you skip the phone tag.
Role-aware answers on products, fit, sizing and resources — instantly, no call required.
Start with OSCAR →Jump to your state's manuals, distributors and certified professionals.
Designers & engineers: run a preliminary, to-the-manual sizing in the OSCAR Calculator.
Open calculatorFor designers, regulators, distributors and project teams that are ready for Lowridge review.
Open project support form public Lowridge line (877) 476-8823
The same role-aware OSCAR guidance, source-library lookup, sizing support, products, manuals and resources — packaged as a polished iPhone app, now available on the App Store.
ASK OSCARLive now · answers in seconds