CHAPIS Emissions Maps

The CHAPIS mapping system is temporarily down

Frequently Asked Questions about CHAPIS

1. Can I see more than one air pollutant at a time?
The CHAPIS maps can only symbolize the emissions of one air pollutant choice at a time in the Legend. However, users can then use either the "Identify" or one of the "Calculate Stats" tools (see FAQ #2) to hyperlink outside of CHAPIS to the ARB's emission inventory database (called CEIDARS, the California Emission Inventory Development and Reporting System) to get more information about each facility, including other reported chemicals. In addition, there are several pick-list choices under "Select pollutant" in CHAPIS that provide values for some combined pollutants (e.g., All Toxic Compounds, Other, and Potency-Weighted Lbs).

2. How do I get to the underlying information for each facility?
There are two main ways to "drill down" to see the complete reported data for a facility.

One is using the Identify tool (the icon above the map that looks like the lettter "i" inside a black circle). Be sure the "Identify Layer" (below the map) is set to "Emissions", then click on a particular facility point on the map. The facility name pops up and is hyperlinked outside of CHAPIS to the ARB's emission inventory database (CEIDARS), which provides more information about each facility.

The other way is to use the "Calculate Combined Stat(istic)s" or "Calculate Point Stat(istic)s" tools. The "Calculate Combined Stats" tool shows the combined (gridded) emissions from all types of sources (e.g., mobile and stationary) for all grid cells in the entire map view, and also provides a list of the facilities in ranked order, each with a hyperlink outside of CHAPIS to the CEIDARS emission inventory data. (A specific pollutant must be selected to use the "Calculate Combined Stats".) The "Calculate Point Stats" is similar and provides a list of facilities in the map view, but does not provide the combined source totals, only point sources.

You can also link directly to the CEIDARS Facility Search web query at: /app/emsinv/facinfo/facinfo.php. However, please be aware that the year 2001 emission inventory has undergone additional review and improvement due to the CHAPIS review process, so some improvements may not be reflected in inventory years other than 2001.

3. What about Pop-Up Blockers? Will they interfere with CHAPIS?
Yes. CHAPIS reports the results of many tools like the Identify or Calculate Statistics tools using temporary pop-up windows. While using CHAPIS, you will need to temporarily disable any Pop-Up Blockers (plug-ins that block advertisements) that you may be using.

4. What web-browser and screen settings should I use?
CHAPIS is best viewed using Internet Explorer (version 5 or higher). Netscape Navigator (version 4.6 or higher) is also generally satisfactory. While using CHAPIS, you will need to temporarily disable any pop-up blocker software that you may be using. For best results, use a screen display setting of 1024 x 768 pixels, and use a "Text Size" setting of Medium (or Small), to ensure that all buttons will be visible without excessive scrolling or re-sizing of windows. (In Netscape Navigator, use the "Decrease Fonts" option to reduce the text size.)

5. When I use "Gridded Emissions", I don't get a window to select the categories or I don't see the "Refresh Map" button. What do I do?
First, be sure you have temporarily disabled any Pop-Up Blocker software you have. For best results, use Internet Explorer (version 5 or higher) for your browser, use a screen display setting of 1024 x 768 pixels, and use a "Text Size" setting of Medium (or Small). This ensures that all buttons will be visible without having to scroll or re-size the windows. (In Netscape Navigator, use the "Decrease Fonts" option for the text size.) The "Refresh Map" button is located at the bottom of the "Gridded Emissions Categories" pop-up window, and it might not be visible if you use a Large "Text Size" or a display resolution like 800 x 600 pixels. Either change the display to 1024 x 768 and the Text Size setting of your browser to Medium, or you can drag the corner of the pop-up box to enlarge the window so that you can see the "Refresh Map" button at the bottom.

6. When I search for my zip code, I get an error message saying my zip code is not found.

The zip code layer used in this initial launch of CHAPIS may not fully cover some zip codes, especially newer or re-designated zip code areas. Zip codes are dynamic, and represent mail carrier routing strategies used by the U.S. Postal Service, rather than real boundaries on land. We are looking into newer and improved data sources that we can include on future internet releases. In the meantime, you may find it helpful to enter a nearby zip code or choose the nearest applicable region from the region picklist, then pan or zoom to your area of interest.


CHAPIS First Page
Community Health | Emission Inventory
This page last updated March 10, 2008