Do You Need a Data Acquisition System? How to Know — and How to Choose the Right Provider
- Feb 16, 2025
- 4 min read
Updated: 6 days ago
A Data Acquisition System — also called a Data Acquisition and Handling System (DAHS) — is software and hardware designed specifically to collect, validate, calculate, and store emissions data for regulatory compliance. It is the system of record for your facility’s air emissions reporting.
If your facility operates a Continuous Emissions Monitoring System (CEMS), EPA regulations impose detailed, ongoing obligations on how your emissions data is collected, validated, calculated, and reported. Meeting those obligations accurately — without data gaps, documentation errors, or audit exposure — is harder than it sounds when you’re relying on general-purpose process systems or manual processes.
A Data Acquisition System (DAS) is purpose-built to handle those requirements automatically. It’s not the only way to manage emissions data, but it’s the most reliable — and the approach used by the vast majority of regulated facilities for good reason.
This guide breaks down what a DAS does, which regulations drive the need for one, how it compares to alternatives, and what Alliance Technical Group provides to regulated facilities across North America.
What Does a Data Acquisition System Do?
A purpose-built DAS handles the full scope of what compliant operation requires:
Continuous data collection from analyzers, opacity monitors, and parametric monitoring equipment
Daily calibration drift checks and automated recording, as required under 40 CFR Part 60 § 60.13
Real-time flagging of out-of-control periods and automatic application of data substitution procedures
Quarterly audit tracking — RATA, CGA, and RAA — per Appendix F, Procedure 1 of Part 60
Emissions calculations using the specific methodologies your permit and applicable regulation require
Long-term data storage with a complete, auditable record — minimum two years under Part 60
Compliance report generation and electronic submissions in agency-required formats, including ECMPS for Part 75 sources
These are not optional features. They reflect the functions your CEMS must perform under federal and state regulation. A DAS is engineered around exactly those requirements.
Which EPA Regulations Apply to Your Facility?
The regulations don’t mandate a DAS by name — they mandate what your monitoring system must do. Use the table below to identify which regulations apply to your facility and what your CEMS is required to handle.
Regulation | Applies To | Key CEMS Obligations | Does Alliance's DAS Handle This? |
40 CFR Part 60 (NSPS) | Power plants, industrial boilers, cement kilns, glass furnaces, chemical plants, and other new source categories |
| Yes. Alliance’s DAS, StackVision, automates daily drift logging, flags out-of-control periods in real time, tracks quarterly audits, and retains your full data record. |
40 CFR Part 75 (Acid Rain Program) | Electric generating units and other affected units under the Acid Rain Program and NOx mass emission programs |
| Yes. Alliance configures StackVision for ECMPS 2.0 submissions (including the JSON format required), manages monitoring plan alignment, and applies correct Part 75 substitution methodology. |
40 CFR Part 63 (NESHAP) | Hazardous air pollutant sources across chemical manufacturing, petroleum refining, pulp and paper, glass, metals, and others |
| Yes. Alliance configures StackVision to the specific NESHAP subpart applicable to your source category, including data handling requirements during out-of-control and maintenance periods. |
Your facility’s operating permit may also impose requirements more stringent than any federal baseline — tighter limits, additional monitoring obligations, or specific reporting formats driven by state or local air agencies. Alliance will configure your DAS to reflect your actual permit, not just the federal standard.
Data Acquisition Systems vs. Alternatives
Some facilities manage CEMS data through plant historians, distributed control systems (DCS), PLCs, or spreadsheet-based processes. The regulations don’t prohibit these approaches — but they create meaningful operational and compliance risk.
What General-Purpose Systems Lack
Plant historians and DCS platforms are engineered for process operations, not EPA compliance reporting. They collect data, but they are generally not built to:
Apply EPA-specific emissions calculation methodologies for your source category and permit
Automatically track out-of-control periods and apply the correct data substitution under Part 60 Appendix F or Part 75
Generate ECMPS-compliant quarterly submissions or other required electronic reports
Maintain the QA/QC audit trail regulators review during inspections
Flag calibration drift exceedances and document the required corrective response
Building these functions into a process system requires custom engineering that your team then owns — and must maintain accurately as regulations and permits evolve.
Where the Risk Shows Up
The practical compliance risk isn’t always a hard violation on day one. It’s the accumulation of undocumented gaps — a missed drift check, the wrong substitution methodology applied, a report in a format the agency can’t process, or a data correction that was never re-submitted.
These are the issues that surface during audits and cost facilities significant time and exposure.
A purpose-built DAS removes most of that risk by design. The regulatory logic is built in and maintained by specialists who track regulatory changes. Your team operates the system rather than engineering it.
Utilizing Alliance 's StackVision™ Data Acquisition System™
Ready to evaluate a DAS for your facility?
Whether you’re replacing a legacy system, evaluating a DAS for the first time, or not sure if your current setup is still aligned with your permit — Alliance Technical Group can help you find out.