# Presentation: 705406

## Stack Configuration Changes

- Louis Nichols
- EPRI CEMS User’s Group
- Nashville
- May 14, 2008

## Possible Configuration Changes

- Conversion of common stack reporting to individual units reporting
- Adding SO2 scrubber to individual unit (with or without bypass stack)
- Adding SCR to individual unit
- Combining individual unit reports into common  stack reports
- Combinations of any or all of the above

## Timing of Configuration Changes

- Best time to change configurations is at end of reporting year
- 2nd time is best at quarter boundary
- Worst time to change configurations is in the middle of quarter

## Software Changes	

- Separating individual unit reporting from common stack reporting should be easier under ECMPS
- ECMPS has a unit stack configuration record for linking units to a specific stack ID.  This link can be ended by entering an end date for the relationship.
- ECPMS also has stack retirement dates
- You should make configuration changes in one format or the other if at all possible.

## Using ECMPS to make configuration changes

- When you change a configuration, do so by editing the existing monitoring plan
- If the change represents a split, report all emissions for that quarter in a common quarterly report through the end of that quarter.
- EPA will separate the monitoring plans as necessary for subsequent quarters.
- Then future emissions reports will also be separated as appropriate.

## Ideal Time to Separate Units

- When the unit that first leaves the common stack goes on outage, separate that unit’s reporting from the common stack reporting
- If possible convert as many units as you can to individual reporting at that time
- Unit must not exhaust through common stack after quarter begins if not reporting on common stack

## Acid Rain Program Summary Record (RT 301)

- Heat input must be reported at the unit level for entire year
- Report pollutant emissions at the unit level for any units that no longer exhaust through the common stack starting from the quarter they start reporting as individual units
- If the quarter is split, report pollutant emissions at unit level from the _**beginning**_ of the split quarter

## NOx Budget Program Summary Record (RT 307)

- Report the heat input for the entire ozone season at the unit level in the unit RT 307
- Report NOx mass emissions at the common stack in the common stack summary record  (RT 307) before separating the unit from the common stack
- Report NOx mass emissions at the unit level summary record (RT 307) after separating the unit from the common stack

## CAIR Annual NOx Program Summary Record (RT 307)	

- Report heat input for entire year at unit level in RT 307
- Report NOx Mass emissions at common stack summary record (RT 307) before separating unit
- Report NOx mass emissions at unit level summary record (RT 307) after separating unit from common stack

## By-Pass Stacks

- Bypass stacks should only be defined as locations if monitored
- A bypass approach code is included in the Monitoring Method Data record for the primary monitoring location since in this case the bypass stack is not defined as a monitoring location
- Adding and Removing by-pass stacks
- Uses a multi-stack (MS) designation when bypass stacks are defined as monitoring locations
- Use the Bypass Indicator in the Monitoring Location Attribute Data record
- Add and remove these stacks using the appropriate activate and retire dates in the Stack Pipe Data record

## Part 75 Guidance

- Chapter 16 of the Part 75 Policy Manual - Questions 16.14 through 16.16 provide guidance on requirements for recertification and diagnostic tests required for newly installed add-on SO2 and NOx emission controls on units or stacks with previously certified CEMS
- Check reporting Instructions

## Question 16.14

- Provides timelines for recertification and diagnostic testing
- References section 75.4(e)
- Sets testing deadline to 90 operating days or 180 calendar days after emissions first exit to the atmosphere through a new add-on SO2 or NOx control that is _**operating**_
- Provision for individual units on a common stack with separate controls to have different timelines (e.g., SCR on individual units)

## Question 16.15

- Recertification and diagnostic test requirements for add-on SO2 and NOx controls
- Recertification requirements in section 75.20(b)
- Examples of recertification events caused by installation of add-on controls – relocation of a CEMS, replacement of an analyzer, installation of a new CEMS, change in critical orifice with different size orifice, and dual-span monitor requirement met with an additional analyzer

## Question 16.15 (continued)

- Events that require diagnostic test are cases where the installation of add-on controls do not involve the relocation of the existing CEMS, replacement of an analyzer, installation of a new CEMS, or a change in dilution ratio
- Only involves adding the low-scale measurement range

## Question 16.16

- Provides for data validation and reporting requirements for units that install add-on SO2 and NOx controls
- For monitoring systems that require full certification or recertification
- For monitoring systems that only require diagnostic testing

## Question 16.16 (continued)	

- For monitoring systems that require full certification or recertification:
- Use the substitute data
- Use data from EPA reference Methods
- Use conditionally valid data from the newly installed CEMS as described in section 75.20(b)

## Question 16.16 (continued)		

**Note:** conditional data validation may be used for the entire window of time allotted to complete testing
- If a certified high range monitor is available to record emissions data, the start of conditional data validation for the low measurement range may be delayed for 60 unit operating days after the emissions pass through the control device