1 Dust Definition: Saguaro West Case Study Julia LesterWRAP DEJF Meeting ENVIRON InternationalNovember 16, 2005

2 BACKGROUND WRAP’s Dust Emissions Joint Forum (DEJF) developed a draft definition of dust to discriminate between natural and anthropogenic sources of dust WRAP sought a feasibility assessment of draft definition – Draft Feasibility Assessment Report with Protocol (May) – Case studies as examples of Protocol application – Recommended revisions of the draft dust definition, if necessary – Implementation support, as resources permit

3 Case Studies Several potential case studies identified Based on latest Causes of Dust results, COHA analyses, other WRAP programs, 2 case studies identified through discussion with WRAP staff and the DEJF: – Saguaro West (SAWE) in Pima County Arizona CoD / CoHA: 123 dust days with soil / coarse mass significant contributors to 20% worst visibility days – Salt Creek Wilderness in New Mexico Interaction with the New Mexico SIP Pilot Project

4 Dust Definition Categories Feasibility Assessment Proposed 3 Categories 1. Anthropogenic 2. Natural (some sources currently not inventoried) 3. Mixed: Natural sources that can be anthropogenically influenced - WRAP interested in partitioning existing dust emission estimates for this category (natural vs. anthropogenic) - Identified data/method resources may be used for new or revised inventories for some sources

5 Feasibility Assessment Protocol 1. Identify the purpose and goals of the analysis 2. Conceptual Model and rank order the dust sources in the project area by chosen criteria 3. Identify major Category 3 sources 4. Identify controls/mitigations, if desired 5. For major Category 3 contributors, are existing methods/databases available to characterize, estimate, and/or partition the emissions? 6. If not, can the necessary methods/databases be developed and at what cost?  If the answers to 5 and/or are yes, definition can be implemented

6 Step 1: Saguaro West (SAWE) Study Purpose and Goals Pilot-scale feasibility assessment (conserve resources for Salt Creek Wilderness assessment) ItemSAWE Case StudyFull-scale Study Analysis area 135  to 225  quadrant, 20-km radius Full 360 area with 20km or more radius Resource identification As in full studyAll Dust source identification LimitedComprehensive, GIS spatially-resolved, long-range sources assessed Dust source characterization Identify models / data for most significant source Identify models / data for all significant sources Ems InventoryMost significantAll significant sources Inv. partitioningMost significant with available data All significant Cat. 3 sources

7 Step 2: SAWE Study Conceptual Model Conceptual Model Elements – Geographic setting – PM and visibility setting Focus of this study is worst dust days for visibility impairment Latest CoD and CoHA results – Geological, topical, ecological, and climatological setting – Land use setting – Summary, including significance threshold

8 Conceptual Model: CoD Information Source: CoD Report, DRI

9 Conceptual Model: SAWE CoHA Information Source: CoHA Report, DRI

10 Conceptual Model: Land Use Source: CoHA Report, DRI

11 Conceptual Model: Land Use Agricultural crops 5 to 10 km SW of Saguaro West Focus area dominated by open shrub/grass lands, with small areas of agricultural row crops and urban uses (Mining activities, if study area expanded) Potential grazing areas not yet identified

12 Conceptual Model: Summary Based on the latest CoD results, case study will focus on worst dust days related to local dust sources – 135 to 225 quadrant focus, radius 20 km (local sources) – April through July have greater CM and fine soil contributions, so seasonal emissions will be reported if they exist

13 Step 2 (cont): Initial Ranking of Sources Table 1. Dust sources likely to affect SAWE Dust Source Type  Description Category Relevance (1-5, 1 being most relevant) Notes Agriculture  Crops  Livestock-grazed Rangeland 12 ~10-km 2 area of cropland km SW of Saguaro West Construction and demolition  Residential area and developments 14 Various scatted residential / light industrial development in SE area of Focus Area Paved and unpaved roadways, including irrigation canal roads 13 Identifying data resources (e.g. 50-m wide irrigation canal running NW to SE from 0.5 km S of SAWE Foot trails  Hiking trail system 15 Surface mining disturbance: 4 quarries, large copper mine SE of SAWE 14 (or 2*)35 to 50 km away

14 Step 2: Initial Ranking of Sources (cont.) Table 1 continued. Dust sources likely to affect SAWE Dust Source Type  Description Category Relevance (1-5, 1 being most relevant) Notes Natural landslides and rockslides25 Landslide incidence low (< 1.5% of area) Extraterrestrial material and impacts25 Wildlife movement  Large mammals (cows, sheep, mule deer, white-tailed deer, pronghorn, peccary) 3 Unknown at this time All areas except urban areas suitable for wildlife Animal burrowing  12 species of carnivores (e.g., coyotes, foxes, bobcats), 3 species of insectivores (shrews), 4 species of lagomorphs (rabbits), 32 species of rodents (gophers, rats, mice, etc.) 3 Unknown, but may be significant All areas except urban areas suitable for wildlife

15 Step 2: Initial Ranking of Sources (cont.) Table 1 continued. Dust sources likely to affect Saguaro National Park. Dust Source Type  Description Category Relevance (1-5, 1 being most relevant) Notes Windblown from undeveloped lands (undisturbed or previously disturbed) 31 Emission from shrub lands probably the highest – need to identify past and current rangelands, if any Areas burned by fires35 Reviewing Fire Forum resources Exposed beds of dry riverbeds and drainages  Brawley Wash and tributaries  Santa Cruz River and tributaries 34 Limited amount of surface water may be diverted for anthropogenic use. Intermittent drainages. Focus Area is covered in small dry intermittent drainages. Windblown PM from sources created by natural events over 12 months previously 35 Reviewing Arizona NEAPs

16 Most relevant: Windblown dust (Category 3) Next most relevant: Agriculture (Category 1) – If the study area was extended to 50 km, surface mining would also be included at this level Emissions from animal movement and burrowing, or the effects of these activities on windblown dust emissions, (Category 3) – relevance cannot be assessed without further investigation Results of Step 5 may indicate the need to re- order the source rankings Step 2/3: Initial Ranking Summary

17 Step 5: Resource Availability for Category 3 Sources For major Category 3 contributors, are resources available to characterize, estimate, and/or partition the emissions? – Data and Model Resource Identification – Dust source characterization – Site-specific dust emission estimates – Emission partitioning

18 Step 5: Resource Identification Southwest Regional GAP Analysis ProjectAttribution of Haze (AoH) data and analyses: Google Earth (aerials)WRAP Technical Support Syatem (under development) National Resources InventoryWRAP Windblown Dust Emission Model Land Condition IndexNRCS PLANTS Database Soil Data Mart: Soil Survey Geographic (SSURGO) database Wildlife Exposure Factors Handbook COHA data: National Museum North American Mammals Database Arizona Meteorological Network (AZMET)Grazing Land Applications Software (GLA) Hydrometeorological Networks in the United States (JOSS) Cumulative Index for the Mammalian Species 32 data/model resources identified for study area (many are in the process of development or revision)

19 Step 5: Dust Source Characterization, Emission Estimation, and Partitioning Most significant SAWE source (windblown dust) resource analysis Source Category Availability of Emissions Data Availability of Partitioning Data Windblown Dust from Row Crops (Category 1) High: Generate via WRAP Windblown Dust Emission Model Not required for Category 1 Dust Source Windblown Dust from Shrublands and Grasslands (Category 3) High: Generate via WRAP Windblown Dust Emission Model Data on vegetation coverage may be available. Vegetation coverage in grazed areas or otherwise humanly disturbed areas could be compared with vegetation coverage in nearby ungrazed reference areas

20 Step 5: Dust Source Characterization, Emission Estimation, and Partitioning Potentially major SAWE source (animal movement, impact of burrowing animals) resource analysis Source Category Availability of Emissions Data Availability of Partitioning Data Large mammal movements (Category 3) Not availableIdentification of legal grazing lands may be possible Burrowing Animal Impacts (Category 3) Direct or indirect emissions estimates are not available Emissions may be higher than assumed through traditional erodibility metrics (see next column) Soil disturbance by pocket gophers is a major source of natural sediment transport and disturbance. Reference area may have higher emissions than currently estimated

21 Step 5: Emission Estimates Windblown Dust – Current windblown dust model estimates – Spatially and temporally-resolved Specific windblown sources considered: – Agricultural lands – Grasslands – Shrublands – Barren lands

22 Agricultural Emissions

23 Grasslands

24 Shrublands

25 Barren Lands

26 Step 5: Emission Summary Shrublands dominant – Grasslands contribute with a significantly lesser contribution from barren lands Agricultural sources in study area appear not to be inventoried Based on current inventory evaluation for non- windblown sources in Pima County: – Ag tilling and mining operations ~ 500 tpy PM10 each – Unpaved roads contribute ~4500 tpy; prevalence in study area unknown but considered low Animal movement, burrowing emissions unknown

27 Step 5: Category 3 Partitioning For windblown dust from shrublands, are there areas that are anthropogenically disturbed or impacted? – Reviewing grazing databases – Searching for unpaved road databases If anthropogenic influences identified, partition based on: – Level 1: areal extent – Level 2: comparison to reference natural area

28 Next Steps Study area finalization Resolve inventory discrepancies Attempt to assess potential relevance of animal-related emissions or impacts Partition scrubland emissions Assess dust definition feasibility Finalize draft SAWE Case Study report by end of year Begin Salt Creek Wilderness Case Study