Nevada County Grand Jury • 2003-2004

Air Quality in Nevada County Cutting Through the Haze Reason for Investigation Measurements of air pollution in the

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Findings and Recommendations 16 findings

F1
Pollution monitoring data show that levels for ozone have increased in Western Nevada County. Since 1997, there has been a steady increase of the number of days and hours when ozone levels have exceeded the State air quality standard. The exceedances3 usually occur in the late afternoon and evening, which indicates ozone and its precursors are transported from upwind (source) area4. (See sources numbers 1 and 2.)
No recommendations for this finding
F2
Ozone and PM10 & PM2.5 particulates are the primary contributors to air pollution in Nevada County. Ozone concentrations are typically low in the winter months but rise 3 The term “exceedance” means the ambient levels of ozone or particulate matter have risen above the applicable Air Quality Standards. 4 “Transport” is the movement of pollutants from an upwind (source) area (Sacramento Valley and Bay Area) to a downwind (destination) area (Nevada County), due to the prevailing Southwest winds. (See source no. 2). dramatically during the summer season. Concentrations of particulates typically increase during the winter months.
No recommendations for this finding
F3
Ozone levels above the Federal air quality standard aggravate the health of people with sensitive and /or compromised pulmonary systems. Ozone is a powerful oxidant that can damage the respiratory tract causing inflammation and irritation, and induces symptoms such as coughing, shortness of breath and worsening of asthma symptoms.
Related Recommendations (1)
R6
The Air Quality District should continue the public awareness programs that illuminate the health risks due to long-term exposure to pollutants such as ozone and PM10, PM2.5 particulates.
F4
PM10 & PM2.5 particulates are contained in smoke from wood stoves and open burning of all types: residential burning; prescribed fire (forest management, wild-lands vegetation management); land development clearing; hazard reduction; agriculture; and road maintenance. These small size particulates get by the natural filtration systems of the nose and throat and lodge deep in the lungs. People most sensitive are those with chronic lung or cardiovascular disease, those with influenza, asthmatics, the elderly and children. Air Quality Index (AQI) vs. Health Hazard (This table used courtesy of Sacramento Metropolitan Air Quality Management District) AQI Health Categories Ozone Fine Particles PM2.5 Particles PM10 300 Active children and adults, People with respiratory or heart People with respiratory Very and people with respiratory disease, the elderly and disease, such as asthma, Unhealthy disease, such as asthma, children should avoid any should avoid any outdoor should avoid all outdoor outdoor activity; everyone else activity; everyone else, 201-300 exertion; everyone else, should avoid prolonged especially the elderly and especially children, should exertion children, should limit limit outdoor exertion outdoor exertion 200 Active children and adults, People with respiratory or heart People with respiratory Unhealthy and people with respiratory disease, the elderly and disease, such as asthma, disease, such as asthma, children should avoid prolonged should avoid outdoor 151-200 should avoid prolonged exertion; everyone else should exertion; everyone else, outdoor exertion; everyone limit prolonged exertion especially the elderly and else, especially children children, should limit should limit prolonged prolonged outdoor outdoor exertion exertion (106 ppb - NAAQS)* 150 Active children and adults, People with respiratory or heart People with respiratory Unhealthy and people with respiratory disease, the elderly and disease, such as asthma, for disease, such as asthma, children should limit prolonged should limit outdoor Sensitive should limit prolonged exertion exertion Groups outdoor exertion (85 ppb - NAAQS)* 101-150 100 Unusually sensitive people Moderate should consider limiting prolonged outdoor exertion None None 51-100 50 Good 0-50 None None None * Measurements are in parts per billion (ppb). 85 ppb is the National Ambient Air Quality Standard (NAAQS) for “Unhealthy for Sensitive Groups.” 106 ppb is the NAAQS for “Unhealthy” category. Any 8-hour average greater than 85 ppb is considered harmful to the public health. Measurement information provided by Northern Sierra Air Quality Management District.
Related Recommendations (1)
R6
The Air Quality District should continue the public awareness programs that illuminate the health risks due to long-term exposure to pollutants such as ozone and PM10, PM2.5 particulates.
F5
Pollution monitoring sites continuously record the levels of pollutants (ozone, PM10, PM2.5) at various locations within the Air Quality District as well as to the south and west of Nevada County. During 2002 at the Grass Valley monitoring site, there were 22 days with exceedances of the 8-hour Federal Air Quality Standard for ozone. There were 80 hours on 20 separate days exceeding the State 1 hour Air Quality Standard for ozone.
No recommendations for this finding
F6
The hot, stagnant days during July 2002 in the Broader Sacramento Area contributed to record high ozone levels as measured at the Grass Valley monitoring site. This ozone was later transported into the Air Quality District on the prevailing southwest winds.
No recommendations for this finding
F7
According to the State Air Quality Board, Western Nevada County’s impending designation as a Federal non-attainment area for ozone is a result of overwhelming air pollution transport from upwind (source) urban areas that include the Sacramento Valley and Bay areas. This graph shows ozone concentration over a two-day period, measured at three locations. The graph shows the transport of ozone from the upwind (source) areas of Sacramento and Folsom into the foothills of Nevada County. As the peak values decrease in the upwind (source) areas, the ozone level rises in the foothills blown in on the prevailing winds. Graph provided by Northern Sierra Air Quality Management District.
No recommendations for this finding
F8
The State Air Resources Board opposes the EPA plan to make Western Nevada County part of the Sacramento ozone area. Nevada County and other downwind (destination) counties have their own pollution control agencies and have “air basins” distinct from their more urban counterparts.
No recommendations for this finding
F9
Improvements in Western Nevada County air quality, with respect to ozone, will depend largely on the success of air quality programs in upwind (source) areas such as the Sacramento Valley and the Bay Area. (See source no. 2.)
Related Recommendations (1)
R1
The Board of Supervisors (BOS) must continue to enlist the support of the California Air Resources Board and state and federal legislators to create Nevada County’s own air pollution non-attainment district. Western Nevada County should be designated as its own non-attainment district with recognition by the EPA and California Air Resources Board that Western Nevada County is subjected to overwhelming transport ozone pollution from upwind sources in the Sacramento Valley area.
F10
Until the upwind (source) Broader Sacramento Area makes substantial gains in its ozone precursor reduction program and State and Federal implemented control programs come into effect, the Air Quality District expects to see continued violations of both Federal and State air quality standards in Western Nevada County. Ozone transport - Air Pollutants generated in the Sacramento Valley are transported to the Nevada County foothills by the prevailing southwest winds causing ozone levels in Western Nevada County to exceed the national 8 hour air quality standard.
Related Recommendations (3)
R2
The BOS and legislators should oppose reduction in funds for the improvement of local district air quality.
R3
The BOS should seek to establish additional ozone and continuous particulate monitoring sites, equipped with a full range of meteorological sensors, on the Western edge of Nevada County (Penn Valley or Lake Wildwood area). These monitoring sites would provide information about transport ozone and particulates blowing from the Sacramento Valley into Penn Valley, North San Juan, and areas North of the Yuba River.
R4
The BOS and legislators must urge the EPA to limit any sanctions imposed on Nevada County to those addressing only the causative factors over which the county has some control or that actually improve air quality in our County.
F11
The Air Quality District reports that The Town of Truckee and Quincy currently exceed the State air quality standard for PM10 particulate matter. Wood stoves, open burning of all types, and windblown road sand/dust are the main sources of particulate matter causing violations within the district.
Related Recommendations (2)
R5
The Air Quality District should continue their community programs that reduce pollutants, encourage vehicle trip reductions, reduce the need for open burning, and encourage woodstove change-outs.
R7
The County Department of Transportation and Sanitation should continue working with the Air Quality District and CalTrans and The Town of Truckee to focus on transportation solutions for reducing vehicle generated emissions and road dust created by winter sanding.
F12
PM2.5 particulates are found in smoke from woodstoves and open burning within the county and from agricultural burning in the Sacramento Valley.
Related Recommendations (1)
R5
The Air Quality District should continue their community programs that reduce pollutants, encourage vehicle trip reductions, reduce the need for open burning, and encourage woodstove change-outs.
F13
The Air Quality District has programs in place to mitigate vehicle exhausts, industrial/equipment emissions, particulate pollution, etc. The Air Quality District has supported the leaf-burning ordinance, green waste pickup, and has done educational outreach programs to residents and schools.
No recommendations for this finding
F14
A small sampling of community programs supported and/or sponsored by the Air Quality District include the curbside greenwaste pickup, woodchipping, free compost bins, Master Composter program, the ban on leaf burning, woodstove change-out, purchase of Compressed Natural Gas (CNG) buses and low emission (Hybrid) vehicles, public air quality alerts, and a public “hot line.” As an example, since the ban on leaf burning went into effect, the Air Quality District reports a 75% decrease in smoke-related health complaints.
No recommendations for this finding
F15
The EPA is seeking to restructure air quality boundaries by folding Western Nevada County into the six county Sacramento region non-attainment area, despite opposition by the State Air Resources Board.
No recommendations for this finding
F16
The State Air Resources Board recognizes that portions of the Air Quality District exceed State Air Quality Standards due to transport of pollutants from upwind (source) areas. As a result, the state has designated Nevada County as non-attainment due to overwhelming transport of ozone from upwind (source) areas. As such, the Air Quality District is required to develop an Attainment Plan to maintain emissions from within the Air Quality District to levels below which violations would occur in the absence of the transport contribution. CONCLUSIONS
No recommendations for this finding

Conclusions 5

No Responses Found 3

Government entities assigned to respond to this report. No response documents have been linked in our database.

Nevada County Board of Supervisors Elected County Office
Northern Sierra Air Quality Management District Agency
Truckee City