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D5254 – Standard Test Method Technical Guide
🗺️ Scope and Site Definition
ASTM D5254/D5254M defines a groundwater site as a single, discrete point capable of producing water or hydrologic data from a natural subsurface stratum. This classification includes wells, springs, seeps, drains, and tunnels. Other sources, such as excavations, bore holes, ponds, and sinkholes, may be classified as groundwater sites when they are shown to be hydraulically connected to the groundwater. The practice covers the minimum set of data elements required for permanent site identification.
💡 Minimum vs. Full Dataset: Note 1 of the standard clearly states that the data elements defined here are not exhaustive. Agencies and companies may require additional data elements as part of their own minimum set. The elements provided are strictly the baseline required to distinguish a site.
📊 Core Data Element Categories
The practice specifies that the minimum dataset must include information capable of distinguishing a site by its geographical location on the earth’s surface, political regimes, source identifiers, and individual site characteristics. These elements align with major water data systems such as the USGS National Water Information System (NWIS).
| 🆔 Category | 📝 Description | 🌍 Primary Purpose |
|---|---|---|
| 🗺️ Geographic Location | Surface location of the site | Coordinates (Lat/Long) |
| 🏛️ Political Regime | Jurisdictional authorities | State, County, Municipality |
| 🔢 Source Identifier | Unique site designation | Well ID, API Number |
| 📐 Site Characteristics | Physical/hydraulic features | Type, Depth, Aquifer Name |
⚖️ Unit Systems and Professional Application
The standard permits values to be recorded in either SI units or inch-pound units, but strictly requires each system to be used independently. The inch-pound system referenced is the gravitational system, where the pound (lbf) represents a unit of force, and mass is measured in slugs. The document emphasizes that it does not replace education, experience, or professional judgment (Section 1.5), nor does it address all safety concerns (Section 1.4). Responsibility for regulatory compliance and field safety remains with the user.
| ⚖️ Unit System | ⚡ Force Unit | ⚖️ Mass Unit | ⚠️ Requirement |
|---|---|---|---|
| SI Units | Newton (N) | Kilogram (kg) | Systems must be used independently. |
| Inch-Pound (Gravitational) | Pound-force (lbf) | Slug |
⚠️ Critical Non-Conformance Risk: Section 1.3 clearly states that combining values from the SI and inch-pound systems results in non-conformance with the standard. Practitioners must select one system and adhere strictly to it for all data recorded for a site. Additionally, this standard must be used in conjunction with, and does not supersede, professional judgment and local regulatory standards of care.
❓ Frequently Asked Questions
🔍 What constitutes a “groundwater site” under D5254/D5254M?
A groundwater site is strictly a single point—not a geographic area. It must be capable of producing water or data from a subsurface natural stratum. Wells, springs, seeps, drains, and tunnels are standard examples. Other features like excavations or sinkholes require proof of hydraulic connection to the groundwater system.
💡 Are the data elements listed in this practice the only ones I need to collect?
No. The practice explicitly defines the minimum set required for site identification. Agencies and companies are encouraged to add more data elements to meet their specific operational, investigative, or regulatory needs. This standard is a baseline framework, not a complete database design.
⚡ How are unit systems handled when using inch-pound units?
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