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MPD Infiltrometer
Modified Philip-Dunne (MPD) Infiltrometer

The MPD Infiltrometer replaces the double ring infiltrometer test for saturated hydraulic conductivity (Ksat), for design and monitoring of stormwater infiltration practices.

Because it is a falling head test, it requires much less water and can be performed in a fraction of the time required for the double ring. Since the calculations and report generation are fully automated by software, summer interns and technicians can easily perform these tests in the field, (Engineer not required). This reduces the costs of procuring values for Ksat, bringing this data within budget for projects of all sizes.

Having a site-specific Ksat value improves the design of infiltration practices, allows verification of construction of these practices, and provides hard data for required annual inspections.


MPD InfiltrometerDouble Ring Infiltrometer
Test Time: 30 to 60 MinutesTest time: 4 to 6 hours
Under 1 gallon of waterHundreds of gallons of water required
AutomatedManual - Labor Intensive
Any person can operateRequires a Licensed Engineer
$100 per test$1,000+ per test
Average multiple tests per siteSingle data point for entire site
All data collection and mathematical processing performed automaticallyHuman error
Immediately download a standardized site reportSpend hours calculating and generating a report

MPD Infiltrometer Demonstration

MPD Documents

MPD Login

MPD Brochure (PDF)

What is Ksat? (PDF)

MPD - Double Ring Comparison (PDF)

Sample MPD Report

What is included in each MPD kit?

Quick Guide to MPD Server


Use the MPD infiltrometer to provide a site-specific Ksat for design of infiltration practices. No more relying on vague ranges provided by soil surveys! Also use it to quickly verify the construction of these practices before authorizing payment to the contractor.

Public Works

Perform annual Ksat tests on all of your agencies rain gardens, infiltration basins, and swales. Easily monitor any changes in infiltration capability over time.


The MPD methodology and calculations have a long history dating back to 1911 with the Green-Ampt theory for estimating infiltration, which incorporates many variables that other methods, such as Darcy's Law, do not. Some of these variables include: Soil Suction Head, Porosity, Hydraulic Conductivity and Time.

Two men, Philip & Dunne, then furthered this research and developed a methodology that incorporated the use of a cylinder, filled with water and measured head drop over time. The subsequent math equations incorporate the Green-Ampt theory to predict the field saturated (or steady state) infiltration rate, also known as Hydraulic Conductivity. Philip and Dunne published their methodology in 1993 for peer review.

The University of Minnesota modified Philip & Dunne's work with a variation to the equation in 2007, renaming the method: Modified Philip Dunne or (MPD). This method has been peer reviewed and vetted in the world-wide academic and scientific communities since 2007, becoming an ASTM Standard in 2018.

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© Copyright 2017 Upstream Technologies
US Patents: #8715507B2, #8663466B2, #9506237B2
CA Patent: #2742207 - manufactured under strict license only