What Is an Emissions Inventory?
An Emissions Inventory is a structured accounting of air pollutant emissions from a site—typically quantified by emission point and by pollutant (e.g., NOx, VOC, CO, SO₂, PM, HAPs), using accepted calculation methods and supporting records.
In Texas, many facilities are captured by the TCEQ Point Source Emissions Inventory (EI) program, which is an annual survey for qualifying industrial sites. For certain sectors (including upstream oil & gas), TCEQ also emphasizes EI applicability based on potential to emit thresholds and other criteria.
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Texas’ most trusted environmental experts – comprehensive by design.
When Is It Required?
You may need an Emissions Inventory when:
- Title V applicability is triggered (major source thresholds) or you are renewing/updating a Title V permit.
- You hold (or are seeking) TCEQ air authorizations under NSR/Title V and must support compliance demonstrations.
- You are required to submit an annual Point Source EI to TCEQ (common for large industrial/chemical/refining/power sites and other qualifying operations).
- A lender, buyer, or counsel requests air compliance diligence for an acquisition, refinancing, or portfolio review (especially when Title V/NSR exposure is present).
- You need defensible emissions estimates to support operational changes, expansions, or permit amendments (NSR applicability analyses, PTE/actuals comparisons).
ESE Partners’ Approach
ESE Partners reduces uncertainty in emissions inventories. Clients value our fast, organized data requests that don’t disrupt operations. We select emission factors practically and document our assumptions transparently, so you can defend the inventory later. Our compliance perspective is Texas-first, grounded in TCEQ permitting and reporting expectations. Our deliverables are clear and support both engineering decisions and deal documentation.
Our Process
- Kickoff + scope confirmation (site boundary, emission units, reporting year, pollutants, due dates)
- Data collection (throughput, fuel usage, hours, stack tests, CEMS/PEMS, maintenance logs, SDS, control efficiencies)
- Source/unit mapping (emission points, control devices, operating scenarios)
- Calculations + method selection (AP-42/vendor factors, material balance, test data, monitoring data—method depends on unit and pollutant)
- QA/QC and reasonableness checks (year-over-year variance, unit consistency, reconciliations to operations)
- Submittal-ready package (tables, calculation files, assumptions memo, and support docs aligned to the reporting pathway)
Regulatory Framework (Texas + Federal)
Emissions inventories frequently intersect with the TCEQ Point Source Emissions Inventory annual reporting program for qualifying point sources. They also intersect with TCEQ air permitting requirements and authorizations, including New Source Review (NSR) and Title V. EPA’s Title V Operating Permit program applies as well, depending on major source thresholds and related obligations.
Risks of Not Completing This Service
Skipping or rushing an EI can create real business exposure:
- Deal friction: buyers/lenders flag air uncertainty, delaying close or increasing escrow/indemnity pressure
- Permit vulnerability: inconsistent actuals vs. permit representations can trigger agency questions during updates/renewals
- Reporting noncompliance: missed or inaccurate annual EI reporting where applicable can create enforcement risk
- Costly rework: poor documentation forces recalculation later (often during a high-stakes audit, renewal, or transaction)
More Environmental Compliance Services
Air Compliance
As an environmental compliance company, ESE Partners provides numerous air compliance services to the oil & gas, energy, chemical, and manufacturing market sectors. Our air expertise includes air permitting (Permits by Rule, Standard Permits, New Source Review, Title V Permits), air dispersion modeling, onsite auditing and inspections, federal and state regulatory analysis, emissions inventory, GHG analysis, and deviation and periodic reporting.
Water Compliance
ESE’s water compliance capabilities include industrial and construction stormwater permitting, stormwater pollution prevention plan (SWPPP) preparation, SPCC planning, FRPs, RMPs, Tier II reporting, TRI reporting, AST/UST registration/permitting, wastewater permitting and reporting, onsite inspections and compliance audits, drinking water assessments, wetlands determinations, and water sourcing/acquisition planning. Our environmental compliance services keep your facilities in line with state and federal regulations.
Industries We Serve
ESE operates in a wide range of industries, all with unique needs and regulatory obligations. We offer experts who understand the broad complexity of environmental challenges faced by today’s businesses.
Oil & Gas Operators
Environmental consulting for upstream, midstream, and downstream operations—due diligence, compliance support, and remediation strategy. ESE helps operators manage regulatory risk and maintain operational continuity in Texas.
Telecom & Data Center Developers
ESE supports telecom and data center development with due diligence, permitting support, and construction-phase compliance. We help teams identify environmental constraints early, manage site risk, and keep schedules intact.
Land Development & Redevelopment
ESE supports developers with site screening, Phase I/II ESAs, and remediation planning for redevelopment and infill projects. We help identify constraints early and reduce delays during entitlement and construction.
Why ESE Partners
Texas’ Most Trusted Environmental Experts – Comprehensive by Design. Clients choose ESE for our Texas-specific air and reporting expertise, with a TCEQ focus. We are one firm that can scale across due diligence, permitting, compliance, remediation, and building sciences. Our responsive teams understand transaction deadlines and operational realities. Our work products are defensible and designed to hold up through audits, renewals, and scrutiny, well beyond the submittal itself.
Need an Emissions Inventory that won’t slow your deal—or your operations?
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Our Environmental Compliance Projects
Construction SWPPP: Restaurant in Central Texas
ESE Partners developed a comprehensive Construction Storm Water Pollution Prevention Plan (SWPPP) to support construction of a new located in Central Texas.
EHS Compliance Support, Air Permitting, and SPCC Plans
ESE Partners conducted comprehensive environmental compliance services for multiple facilities located in South Texas, including Spill Prevention, Control, and Countermeasure (SPCC) plan development and air permitting support.
Efficient Air Permitting for New Transfer Operations
A bulk liquid storage and transfer operator sought to launch a new ethanol transloading operation involving rail-to-truck transfers using closed-loop loading.
Frequently Asked Questions About Emissions Inventory Services
What is an emissions inventory?
An Emissions Inventory (EI) is a structured accounting of air pollutant emissions from a site, typically quantified by emission point and by pollutant, such as NOx, VOC, CO, SO₂, PM, and hazardous air pollutants (HAPs), using accepted calculation methods and supporting records. In Texas, many facilities are covered by the Texas Commission on Environmental Quality (TCEQ) Point Source Emissions Inventory program, an annual survey for qualifying industrial sites. For certain sectors, including upstream oil and gas, TCEQ also emphasizes EI applicability based on potential-to-emit thresholds and other criteria.
When do I need an emissions inventory?
You may need an EI when Title V applicability is triggered by major source thresholds, or when you are renewing or updating a Title V permit. You may also need one if you hold or are seeking TCEQ air authorizations under New Source Review (NSR) or Title V and must support compliance demonstrations, or if you are required to submit an annual Point Source EI to TCEQ, which is common for large industrial, chemical, refining, and power sites and other qualifying operations. A lender, buyer, or counsel may request air compliance diligence for an acquisition, refinancing, or portfolio review, especially when Title V or NSR exposure is present. You also need defensible emissions estimates to support operational changes, expansions, or permit amendments, including NSR applicability analyses and comparisons of potential to emit with actual emissions.
What are the risks of skipping or rushing an emissions inventory?
Skipping or rushing an EI can cause deal friction when buyers and lenders flag air uncertainty, delaying closing or increasing escrow and indemnity pressure. It can create permit vulnerability, because actual emissions that are inconsistent with permit representations can trigger agency questions during updates or renewals. Missed or inaccurate annual EI reporting, where applicable, can create enforcement risk. Poor documentation also forces costly rework, with recalculation often happening during a high-stakes audit, renewal, or transaction.
What does ESE Partners’ emissions inventory process look like?
ESE Partners starts with a kickoff and scope confirmation covering the site boundary, emission units, reporting year, pollutants, and due dates. We collect data such as throughput, fuel usage, hours, stack tests, continuous and predictive emissions monitoring data (CEMS and PEMS), maintenance logs, safety data sheets, and control efficiencies, then map sources and units, including emission points, control devices, and operating scenarios. We select calculation methods based on the unit and pollutant, using AP-42 or vendor factors, material balance, test data, or monitoring data, and run QA/QC and reasonableness checks for year-over-year variance, unit consistency, and reconciliation to operations. The final submittal-ready package includes tables, calculation files, an assumptions memo, and supporting documents aligned to the reporting pathway.
