ASTM D8550-25 PDF

Full title and description

Standard Test Method for Determination of Infiltration Rate and Calculating Field Hydraulic Conductivity of Field Soils by Sealed Single‑Ring Infiltrometer and Multiple Pressure Head Procedure — a field test method that specifies a sealed single‑ring infiltrometer technique with multiple pressure heads to measure infiltration rate and to calculate field hydraulic conductivity (Kf) for natural and processed soils.

Abstract

This standard describes procedures for performing sealed single‑ring infiltrometer tests using two consecutively ponded heads (multiple head analysis) to obtain infiltration rates and to estimate field hydraulic conductivity and matric flux potential. It clarifies applicable infiltration rate limits, required apparatus and data analysis (including Green‑Ampt/reynolds & Elrick style analysis), and common sources of error. Typical applications include stormwater management, bioretention evaluation, septic field assessment, irrigation planning, and recharge studies.

General information

• Status: Active standard (designation D8550‑25).
• Publication date: 2025 (designation year shown as “‑25”; see DOI D8550‑25).
• Publisher: ASTM International.
• ICS / categories: 13.080.40 (Soil — geological and geotechnical testing).
• Edition / version: D8550‑25.
• Number of pages: 8 pages.

Scope

This test method applies to field measurement of infiltration rate using a sealed single‑ring infiltrometer equipped to supply constant high‑ and low‑pressure heads and steady ponded water levels, and to the subsequent calculation of field hydraulic conductivity (Kf) using multiple pressure head data. It is intended for natural and processed soils within an infiltration rate range of approximately 2.5 mm/h to 1200 mm/h and for temperatures typically between 0 and 50 °C. It is not intended for use on hydraulic barriers (e.g., landfill liners), soils that experience volume change during infiltration (collapsible or expansive soils), or tests performed below the groundwater table. Reporting is in SI units.

Key topics and requirements

• Sealed single‑ring infiltrometer apparatus and correct installation depth and sealing practice.
• Use of two consecutively ponded heads (multiple head analysis) to determine field hydraulic conductivity and matric flux potential.
• Applicable infiltration rate limits: approximately 2.5 mm/h to 1200 mm/h.
• Data analysis methods (Reynolds & Elrick approach; estimation of Green‑Ampt wetting front pressure head).
• Factors affecting results (soil structure, layering, surface condition, macropores, lateral flow, head, temperature).
• Reporting requirements in SI units and note on limitations and uncertainty (recommendation for replicate tests and statistical treatment).

Typical use and users

Common users include geotechnical and environmental engineers, stormwater and landscape designers, soil scientists, consultants performing pre‑construction and post‑construction site evaluations, practitioners designing bioretention/rain garden systems, septic system designers, and researchers studying infiltration/recharge. Typical uses are stormwater management design, verification of infiltration rates for bioretention, evaluation of leaching and drainage, irrigation planning, and recharge assessments.

Related standards

This test method references and complements other ASTM practices and test methods used for on‑site soil and infiltration assessment, including practices for septic system evaluation (examples noted in the standard: ASTM D5879 and D5921) and quality/practice guidance such as Practice D3740. The method’s analysis approach draws on established infiltration theory (Reynolds & Elrick; Green‑Ampt concepts).

Keywords

infiltration rate, field hydraulic conductivity, sealed single‑ring infiltrometer, multiple head analysis, multiple pressure head, Green‑Ampt, matric flux potential, Reynolds & Elrick, stormwater, bioretention, septic field, soil testing.

FAQ

Q: What is this standard?

A: ASTM D8550‑25 is a field test method for measuring infiltration rate with a sealed single‑ring infiltrometer and for calculating field hydraulic conductivity using a multiple pressure head procedure.

Q: What does it cover?

A: It covers apparatus, field procedures for two consecutively ponded heads, data collection and analysis to compute infiltration rate and field hydraulic conductivity (including multiple head analysis and estimation of wetting front pressure), applicable soil and rate ranges, limitations, and reporting in SI units.

Q: Who typically uses it?

A: Geotechnical and environmental engineers, stormwater/landscape designers, soil scientists, consultants, and researchers who need field measurements of infiltration and Kf for design, permitting, and performance verification.

Q: Is it current or superseded?

A: The designation D8550‑25 indicates the 2025 issuance of the standard; it is listed as an active ASTM standard (D8550‑25). Users should confirm the most recent status or any corrigenda from ASTM before citing for contractual or regulatory purposes.

Q: Is it part of a series?

A: It is part of the ASTM D series of standards for soils and geotechnical materials and was developed under Subcommittee D18.04; it appears in ASTM’s Book of Standards volume covering soil and rock testing. Related soil/infiltration standards and practices (e.g., D5879, D5921, D3740) are commonly used together.

Q: What are the key keywords?

A: infiltration rate; field hydraulic conductivity; infiltrometer; multiple head analysis; sealed single‑ring; Green‑Ampt; matric flux potential.