Compliance

Compliance Requirements

Once a source has received an air quality permit, it is important to stay in compliance with all of the permit conditions included. The federal PSD permitting process and Title V program require that each PSD permit, Title V permit specifies the regulations applicable to the permitted source. Furthermore, the PSD permit also specifies how compliance will be determined for each applicable regulation. The methods to determine compliance and the EPA Compliance Assurance Monitoring program are discussed in the following.

Methods to Determine Compliance

The PSD permit and Title V permit applications must identify both requirements applicable to the facility and any emission units and how compliance with those applicable requirements will be determined. The elements in demonstrating compliance include compliance monitoring, record keeping, and reporting.

Direct Measurement of Air Emission Rates

The basis of direct measurement is the group of procedures published by the EPA in 40 CFR Part 60, Appendix A (Title 40 – Protection of Environment; Part 60 – Standards of Performance for New Stationary Sources and all Test Methods revised as of 1 July 1991). Table 4.11 presents the EPA methods for direct measurement of air emission rates from stationary sources and their group of procedures presented in Appendix A including measurements of gaseous contaminants, specific metals, and VOCs. These methods contain precise standards for performing the procedure, with QA/QC steps, and specify which data to record. Not following the procedure to the latter seriously risk the integrity of the results and jeopardizes their approval. The general procedure for collecting a sample from an exhaust stack for analysis is found in Methods 1–5, as are guidelines on setting up a testing train. The integrity of any test depends on ensuring the sampling train is a closed system with minimal outside (clean) air leakage, which would dilute the concentration of the contaminant in the exhaust sample.

Table 4.11 USEPA methods for direct measurements of air emissions and the group of procedures published by the EPA in 40 CFR Part 60, Appendix A.

Methods, stationary sources	Procedures and pollutants of interests
1	Sample and velocity traverses for stationary sources
2	Determination of stack gas velocity and volumetric flow rate (type S pitot tube)
4	Determination of moisture content in stack gases
5	Determination of PM emissions from stationary sources
6	Sulfur dioxide
7	Nitrogen oxides
8	Sulfuric acid and sulfur dioxide
9	Opacity monitoring
10	Carbon monoxide
11	Hydrogen sulfide content in flue‐gas streams in petroleum refineries
12	Lead
13	Fluoride
15	Hydrogen sulfide; carbonyl sulfide; carbon disulfide
16, 16A	Reduced sulfur compounds
18, 24, 25	VOCs
201, 202	PM₁₀^a

^a PM that is 10 μm or less in diameter.

Method 1 contains guidance for the selection of sampling ports and traverse points for acceptable sampling of a representative aliquot of exhaust. A key concern is collecting a uniform sample over time. It contains procedures for determining whether cyclonic or swirling flow exists. Method 2 contains the procedure for measuring exhaust velocity and volumetric flow rate.

Figure 4.15 is a schematic of a typical sampling train (this particular setup is used to measure PM emissions). Method 5 contains guidance for measuring PM from two sources: filterable PM and condensable PM (the latter is found condensed in impingers down‐stream of the filter). Typically, the PM measured in both locations must be combined. Other Method 5 procedures exist for specific circumstances from specific sources types (i.e. wood heaters, asphalt industry, etc.). Methods 201 and 202 are tests that should be considered for condensable ultrafine PM (Cooper and Alley 2011; Karell 2017).

**Figure 4.15** A process train to measure PM emissions.Source: Adopted from USEPA (1991b).

EXAMPLE 4.14

Check for Emission Standards Compliance

As a consulting engineer, you have been contracted to modify an existing control device used in fly ash removal. The standards for emissions have been changed to a total numbers basis. Determine if the unit will meet an emission standard of 10^5.7 particle/acf. Data for the unit are given below:

Average particle size, d _p = 10 μm, assume constant
Particle specific gravity = 2.3
Inlet loading, IL = 3.0 gr/ft³
Efficiency (mass basis), E = 99.5% = 0.995

SOLUTION

The outlet loading (OL) is given by

Assume a basis of 1.0 ft³

Allowable number of particles/ft³ = 10^5.7 = 5.01 × 10⁵ < 8.0 × 10⁵ images

Therefore, the unit will not meet the particle emission standard.

EXAMPLE 4.15

A sample stream of dry gas is being withdrawn from a stack. The stack gases are 200 °C and 730 mm Hg. The stream flows through a heated filter, a set of cooled impingers, a small air pump, and then through a flow meter, as shown in Figure 4.15. The rate of flow is determined to be 30.0 l/min at 20 °C and 790 mm Hg.

Calculate the actual volumetric flow rate through the filter (at T = 200 °C and P = 730 mm Hg).
If 1.32 mg of solid particles is collected on the filter in 30 minutes, calculate the concentration of particles in the stack gas (in μg/m³).

SOLUTION

Q _filter = (30.0) = 52.41 l/min
Total volume of gas sampled (at stack condition):

EXAMPLE 4.16

A stack (T = 550 °F and P = 750 mm Hg) was sampled using EPA Method 5 (see Figure 4.15).

The total gas volume that flowed through the dry gas meter was 2.785 m³ (at T = 60 °F and P = 800 mm Hg). The mass of PM collected was 1.50 g. Also, 72.0 g of H₂O was collected in impingers.

Calculate the concentration of PM in the stack (μg/m³) at stack conditions.
The stack gas exits at an average velocity of 20 m/s, and the stack has an inside diameter of 5 m. What is the emission rate of PM in kg/day?
What is the PM concentration in μg/dscm?

Given: