# Presentation: 337631

## 8th Conference on Air Quality Modeling – A&WMA AB-3 Comments on CALPUFF Implementation Issues

- By
- Mark Bennett, CH2M HILL

## CALPUFF Implementation

- Reaffirm support for CALPUFF
- agreement beneficial
- Specific concerns and recommendations
- may serve as template for future models
- General recommendation for more active EPA oversight

## General Concerns

- Availability of model developments and associated documentation
- considerable lag time
- Consistency, availability, and quality of mesoscale data sets
- Lack of methodology for evaluation of wind fields
- Inconsistent guidance from local and federal agencies

## Official Regulatory Version

- Concerns
- Official version has known errors
- Beta version with fixes not official
- Recommendation
- EPA ensure timely maintenance of the CALPUFF code
- EPA provide adequate funding for a “point of contact” where questions can be answered reasonably quickly and accurately

## Users Guide

- Concerns
- Users guide out of date and incomplete
- Request for up-to-date and complete Users Guide made at 7th Modeling Conference (June 2000)
- Recommendation
- EPA ensure up-to-date and complete Users Guide corresponding to official version of CALPUFF is available

## Meteorological Data

- Concerns
- Inconsistent acceptability
- No obs vs Obs
- MM5 (and which MM5), RUC, ETA
- 36 km vs 12 km vs 4 km
- Availability
- Adequacy
- Proposed increase to 5 yrs
- Recommendations
- EPA oversight for consistency and adequacy
- EPA should collect and distribute at cost

## Complex Winds

- Concerns
- Anticipated increased use
- Not as thoroughly evaluated
- Recommendations
- EPA should catalogue and make available
- possible solicit input from the modeling community
- Reactivate Model Clearinghouse

## AERMOD-like Dispersion

- Concerns
- 8/10/2001 Irwin recommends “AERMOD-like” dispersion
- MDISP = 2 (to select similarity sigmas)
- MPARTL = 1 (turns on partial plume penetration effects into elevated inversions)
- MPDF = 1 (turns on convective pbl dispersion)
- Inconsistent acceptability
- Not as thoroughly evaluated
- Recommendations
- Clear guidance
- EPA should catalogue and make available
- solicit input from the modeling community
- Reactivate Model Clearinghouse

## Visibility Analysis

- Concerns
- Most critical use in PSD permitting
- EPA defers to FLMs
- Most contentious issues
- aqueous phase chemistry
- ammonia (lacking guidance, data, etc.)
- overprediction of nitrates in winter
- User frustrations
- Recommendations
- EPA take over guidance for CALPUFF, including visibility
- Upgrade aqueous phase chemistry
- Regulatory guidance on ammonia, etc.
- EPA should catalogue and make available
- solicit input from the modeling community

## Summary

- EPA clearly and definitively take over regulatory guidance for CALPUFF
- EPA should ensure support and timely “model maintenance,” esp. in light of future non-traditional model approval
- EPA actively collect and make available met data, case studies, etc.
-  EPA reactivate and actively maintain the Model Clearinghouse

## List of High Priority Items

- Official version free from known errors
- with associated Users Guides
- Visibility
- Mesoscale met data sets
- Methodology to evaluate CALMET wind fields
- Complex wind fields
- AERMOD-like dispersion