PM Transport Issues-Clark County

Regional Transported Dust To The Las Vegas Valley From Mojave and Sonoran Desert AreasCDAWGNovember, 2013

1

Transported Dust Presentation OverviewClark County PM10 monitoring networkClark County PM10 design valuesJuly 3, 2011 transported dust eventMay 10, 2012 transported dust eventApril 15, 2013 transported dust/high-wind eventConclusions and suggested next steps

2

Clark County PM Monitoring Network3

Clark County Monitoring Network - Urban Core

Transported Dust Routes Into LVV5

Where Is All This Dust Coming From?July 3, 2011 PM10 Transported Dust EventMeteorology assessment indicates desert sources south of Bullhead City, Arizona (Haboob)Low velocity winds transported the airborne dust from Bullhead City to the Las Vegas ValleyWinds picked up in afternoon and cleared transported dust out of the Las Vegas Valley - Local wind driven sources did not contribute to the high PM concentrations

6

Source: Desert Meteorology. Thomas T. Warner. 2004

Desert Storm Haboob

12hr Backward Trajectory HYSPLIT for Boulder City and J. D. Smith DAQ Monitoring Stations July 3, 2011 10:00 PST

Where Is All This Dust Coming From?May 10, 2012 PM10 Transported Dust EventMeteorology assessment indicates northwestern Arizona Haboob/Weather event near Phoenix, Arizona pushed large desert storm dust concentrations into the Eldorado Valley (Boulder City) corridor into the Las Vegas ValleyWinds picked up in afternoon and cleared transported dust out of the Las Vegas Valley to the Northwest - No local sources of dust in Las Vegas Valley added to the mix

HYSPLIT at the Boulder City and Jean DAQ Monitoring Stations for 10MetersAbove Ground LevelNote: NOAA HYSPLIT model shows two different source regions; one out of California and the other from northwestern Arizona. However, the bulk of the dust came from the northwestern Arizona desert storm (HABOOB).

Attainment StatusLas Vegas ValleyPM10 Monitoring SiteAverage (g/m3)Site Design Value (g/m3)201020112012Paul Meyer48103147103Sunrise Acres57858166Joe Neal641308867Green Valley52143145125Palo Verde498913889JD Smith62718265Jerome Mack--138138PM10Design Values

*Excludes exceptional events that have been flagged

Dust Transport Event (May 10, 2012)

Dust Transport Event (July 3, 2011)13

Where Is All This Dust Coming From?

April 15, 2013 PM10 Dust Transport/High-Wind Event Meteorology assessment indicates dust was transported from sources in the desert east of Edwards AFB and the cities of Barstow and Baker, California and the Jean dry lake bed, in the Ivanpah Valley (Southern Nevada)Dust followed the transportation corridor to the Las Vegas Valley; the I-15 corridor

Dust Transport/High-Wind Event (April 15, 2013)

PM10 Exceedance Concentrations for the Day:

Palo Verde 213 g/m3Paul Meyer 165 g/m3Joe Neal 227 g/m3Sunrise Acres -268 g/m3J.D. Smith - 238g/m3Green Valley - 197g/m3Jean (Ivanpah Valley) - 169g/m3Boulder City (Eldorado Valley) 246 g/m3

15

A strong pre-frontal trough moved through the Baker, and Barstow, California area on the 14th which raised a large amount of dust. The large mass of suspended dust moved north, east and into parts of southern Nevada and northwest Arizona. The high winds over the western Mojave Desert continued to transport suspended dust into Clark County for most of the day. Additional information on April 15, 2013 Transported Dust/High-Wind Event:

17

18

Desert Dust Storm Haboob

ConclusionsConditions exist that are out of our controlTransport follows I-15 corridor out of the Mojave Desert and the 93/95 corridor out of the Sonoran/Mojave DesertContinued impacts from high-wind eventsTransported dust is major contributor to high/elevated PM concentrations in Clark County for the past 3 4 years and the trend is continuingModeling analyses indicate that transported/high- wind dust events in the Las Vegas Valley do not impact other areas either to or towards the Grand Canyon (Visibility degradation) or areas immediately north-north west of the Las Vegas Valley 20Suggested Next StepsFacilitate multi-state collaborative efforts to address pollutant transport issuesRe-activate the Best Available Control Measure Working Group (BACM) Provides mechanism for collaboration between air agencies in the desert southwest (AZ, CA and NV)Group can focus on transport issues, involving Particulate Matter and Ozone, including impacts from wildfires and high-wind events

Suggested Next Steps (continued)Share modeling data and collaborate on refining input data Collaboratively share and analyze modeling resultsCollaboratively develop approaches to reduce emissions from major sources of dust in the desert southwestCollaborate on atmospheric field measurement studies and mutually support other agencies studies, to the extent possible

23

Questions?

Russell Merle: 702-455-1662Rodney Langston: 702-455-1661

23