NETTINGRick Goertz, P.E.Air Permits DivisionTexas Commission on Environmental QualityEnvironmental Trade Fair 2013NETTINGNETTING!

The Netting Zone!

Why Do Netting?How do you know if a modification is a major modification triggering major NSR?You conduct a netting exercise.About NettingApplies to existing major sources only.Ensures smaller projects do not add up to be a major modification.An evaluation of : The current project, plus Increases and decreases within the contemporaneous period (netting window).Contemporaneous PeriodNetting Window

Five years before start of construction Proposed start of operationNettingContemporaneous PeriodNetting WindowModifications identified within the contemporaneous period may be based on: The date the modification was authorized, or The date the change is operated.Must be used consistently.Indicate which method is used.Creditable EmissionsOccurs during the contemporaneous period.Cannot have been relied upon in issuing a major NSR permit for the source.Sources/activities authorized by the major NSR permit are not in operation when the current increase is authorized.Rely on Emissions Inventory.Creditable IncreasesThe new level of emissions exceeds the baseline actual emission rate.(PTE Baseline = Increase)Does not include emission increases at facilities under a plant-wide applicability limit (PAL). Creditable DecreasesThe baseline actual emission rate exceeds the new level of emissions.Enforceable at and after the time that project modification begins to operate. (Must be enforceable and real before the unit starts operation).Creditable EmissionsContdIdentify increases and decreases in TCEQ Table 3F.The project number that authorized the modificationProvide an explanation if a project is not included in the evaluation.Each creditable decrease should be accompanied by TCEQ Table 4F.Determining Increases and DecreasesIncreases and decreases for each project within the contemporaneous period are determined based on a comparison of the following: Baseline actual emission rate, and The PTE of that project (projected actuals are not used in this step except for the current project).Baseline Actual Emission RateEmissions, in tons/year, actually emitted during a consecutive 24-month period out of the previous 10 years (previous 5 years for electric utilities) from the date the project is authorized or modifications are operated.Using an Allowable to Allowable ComparisonSituation #1: the baseline actual > current PTESituation #2: a new facility is within 2 years of its initial start-up dateNetting Window ExampleNet Emissions IncreaseProject increase+Non-project source-wide creditable contemporaneous emission increasesSource-wide creditable contemporaneous emission decreasesThe amount that exceeds zeroTriggering Major NSRCompare the net increases to the appropriate significant emission rate.If the increase is greater than or equal to the significant emission rate for the pollutant, major NSR is required.Time for some examples!

Example 1Company is a named major source, in a serious nonattainment area.Current PTE = 50 Tons/year NOXProposed PTE = 60 Tons/year NOXBaseline Actual = 47 Tons/year NOXProject Increase = 13 Tons/year NOX (Proposed PTE Baseline Actual)Current PTE= 50 Tons/year NOX

Proposed PTE= 60 Tons/year NOX

Baseline Actual= 47 Tons/year NOX

Project Increase= 13 Tons/year NOX(Proposed PTE-Baseline Actual)

Example 1ContdMajor Source, Serious Nonattainment, Current PTE = 50, Proposed PTE = 60, Baseline Actual = 47, Project Increase = 13Emission increase exceeds the netting significance level of 5 Tons/year.Netting is required!Example 1Table 3F

NOxExample 1Finding Total IncreaseCurrent Project 13 Tons/year increase11/2010 Project 5 Tons/year increase10/2011 Project 0.25 Tons/year increase - 4.25 Tons/year decreaseTotal Increase: 14 Tons/yearCurrent Project 13 Tons/year increase11/2010 Project 5 Tons/year increase10/2011 Project 0.25 Tons/year increase - 4.25 Tons/year decreaseTotal Increase: 14 Tons/yearExample 1Nonattainment?The major modification significant emission rate for a severe nonattainment area is 25 Tons/year. Net project increase is 14 Tons/year.The project is not a major modification and major NSR (nonattainment review) is not required.

Check Your Calculations!

Example 2Company is a named major source located in a serious nonattainment area. Company has four steam boilers operating under a cap.Boiler 1: 25 Tons/year NOXBoiler 2: 25 Tons/year NOXBoiler 3: 25 Tons/year NOXBoiler 4: 25 Tons/year NOXCurrent PTE: 100 Tons/year NOX

Example 2Contd

Company request :Increase firing rate of one boiler, its NOX emissions increase by 3 Tons/year.New contribution of one boiler is now 28 Tons/year NOX.Example 2More DataCurrent PTE = 100 Tons/year NOXProposed PTE = 103 Tons/year NOXBaseline Actual = 90 Tons/year NOXExample 2Is Netting Required?Is the project increase significant such that netting is required?Company proposes:28 Tons/year 25 Tons/year = 3 Tons/year NOX increaseIs this a valid approach?Example 2AnswerNNNooooooooooo !Its not a valid approach...Should we ask why ?

Example 2ExplanationThe cap is increased from 100 Tons/year to 103 Tons/year.The cap is being increased for all boilers.Increasing the cap means relaxing a federally enforceable emission limit.All units under the increased cap are modified.Example 2Is Netting Required?Is the project increase significant?103 Tons/year (Proposed PTE) 90 Tons/year (Baseline actual) 13 Tons/year NOX increaseThe project increase is significant (increase > 5 Tons/year) so...Netting is required!

Example 2An Alternate ApproachSet a separate enforceable limit for the affected boiler. Project increases are determined based on the individual boiler rather than for all the boilers.Netting may be avoided.Example 3A small tank farm with three emission points has three projects (modifications) within the contemporaneous period, including the current project.Example 3 Current Proposal Table

Using the traditional method, the total increase would be 35 tpy (8+17+10). Of that 35 tpy, 28 tpy (8+10+10) are attributable to EPN1.

Example 3ContdThe increase is greater than the final allowable emission rate (26 tpy) indicating that portions of the increase have been counted more than once.Increases in emissions can be better reflected by using the endpoints method for EPN 1.Increase or DecreaseIncrease = Final PTE Baseline actuals from earliest project.Net increase is 16 tpy (26 tpy 10 tpy). Method can only be used when determining net emissions increase. Baseline always used to determine project increase.

Example 3Endpoints NettingUsing endpoints netting: The contribution of EPN 1 = 16 tpy The total project net increase = 23 tpy

Example 3 Table 3FNow you are ready to go out into the world and NET!Disclaimer: The presenter does not guarantee the hearing of sound effects during the performance of actual netting exercises.Now you are readyTHE ENDThank You, Thank You Very Much.

ContactsJOHNNY VERMILLION(512) 239-1292Or Rick Goertz(512)239-5606Other3265.3103Other1776.3258Other1776.3258