Aufstellung von Luftreinhalteplänen und Plänen für kurzfristige Maßnahmen

Despite considerable progress in technical environmental protection, the air we breathe - especially in cities - is still polluted. Successes in reducing particulate matter pollution cannot hide the fact that the concentration of pollutants that the World Health Organization has declared to be harmless has not yet been reached. For example, high concentrations of nitrogen dioxide on busy roads contribute to the health problems of local residents. Further targeted measures to reduce emissions will therefore be necessary in the future.

The European Union has given high priority to protecting human health and the environment from high concentrations of air pollutants with the directive of the same name (2008/50/EC). Limit values for air pollutants, standardized measurement methods and uniform assessment criteria for air quality lead to better comparability of pollution in the member states and establish uniform requirements for air pollution control. The directive was transposed into German law in the Federal Immission Control Act (BImSchG) and the Ordinance on Air Quality Standards and Emission Ceilings (39th BImSchV).

According to EU regulations, each country must be divided into agglomerations and zones. Agglomerations are^{characterized} in particular by a population density of 1,000 inhabitants or more per square kilometer (^km2) and an area of at least 100 km2. Hesse is divided into two conurbations (Rhine-Main and Kassel) and three areas (Central and Northern Hesse, Lahn-Dill and Southern Hesse).

Air pollution control is based on monitoring air quality as comprehensively as possible. To this end, the concentrations of a range of air pollutants are measured at various locations, e.g. at traffic hotspots, in the urban background and in rural areas. The minimum number of measuring points is determined depending on the number of inhabitants and the existing air quality. All air pollutants for which limit values are set by law are measured, but not all pollutants are measured at every monitoring station. For example, benzene is only measured at traffic hotspots, while ozone is only measured in the urban background and in rural areas. Due to their particular relevance to health and the exceedances recorded, the measurements of the particle fractions (PM10 and PM2.5) and nitrogen dioxide (_NO2) are of particular importance.

The limit value for PM10 is 40 µg/m³ as an annual average and 50 µg/m³ as a daily average with 35 permissible exceedances per year. The limit value for the finer particle fraction PM2.5 is 25 µg/m³. The limit value for _NO2 is 40 µg/m³ as an annual average and 200 µg/m³ as an hourly average with 18 permissible exceedances per year.

If an immission limit value is exceeded, a clean air plan (LRP) must be drawn up. The aim of the measures defined in this plan is to keep the period in which the limit value is exceeded as short as possible.

If there is a risk of alarm thresholds being exceeded that are much higher than the limit values, a plan for short-term measures must be drawn up. The measures described in these plans must take effect in the short term with the aim of reducing the risk of the alarm threshold being exceeded or limiting its duration. Alert thresholds for triggering the preparation of a short-term action plan are currently defined for _NO2 and _SO2. To date, these alert thresholds have not been exceeded in Hesse.

For the air pollutant ozone, the EU has only set a target value that must be met within a certain period of time if possible. The public is informed in particular about the type and extent of the exceedance as well as possible behavioral recommendations when ozone alert and information thresholds are exceeded.

Exceedance of an immission limit value (clean air plan) , risk of exceeding an alarm threshold (plan for short-term measures).

If air monitoring stations register that immission limits have been exceeded, clean air plans must be drawn up within two years of the exceedance becoming known. The clean air plans are drawn up and updated by the Ministry of the Environment. In close cooperation with the local authorities concerned, measures are defined that should lead to a permanent reduction in pollution levels. In the case of measures that restrict or prohibit traffic, agreement is reached with the responsible road construction and road traffic authorities. When drawing up and amending clean air plans, the public is involved by displaying the draft plan in the municipalities concerned and on the Internet. The public has the opportunity to submit concerns, suggestions and comments on the draft plan.

As part of the public participation process, the Clean Air Plan will be published for a period of one month and two weeks. During this period, objections, suggestions and concerns can be submitted in writing to the Ministry of the Environment.

The Ministry of the Environment (HMUKLV) is responsible for drawing up and updating the clean air plans.

The Hessian State Office for the Environment and Geology (HLUG) is responsible for operating the air monitoring network and informing the public about measured values and exceedances.