On 19.10.2023, immediately after the increase of sulphur dioxide values in the air of Dimitrovgrad was detected, the Regional Inspectorate for Environment and Water (RIEW) - Haskovo promptly issued a prescription to TPP Maritsa 3 AD to take urgent effective measures to reduce the mass flow of sulphur dioxide formed as a result of its production activities.

The actions taken by the operator upon the control by the Regional Inspectorate for Environmental Protection resulted in a sharp reduction of sulphur dioxide values, after on 19.10.2023 at 16:00 an exceedance of 1.15 times the limit value of the hourly average standard was recorded. The recorded value of 402.60 µg/m³ for sulphur dioxide in the ambient air of the city is a short-term exposure.

The level of sulphur dioxide concentration in ambient air above which a risk to human health is considered to exist and specific measures need to be taken for prevention purposes is 500 μg/m³ measured over three consecutive hours. This is defined as an alert threshold and no exceedance of this threshold for sulphur dioxide has been recorded in Dimitrovgrad so far in 2023.

In the following hours of the day the recorded values of sulphur dioxide from the AIS "Rakovski" in Dimitrovgrad were within the limits and in the range of 12.00 to 19.00 μg/m³. The day/night average value for 19.10.2023 for sulphur dioxide was 34,56 μg/m³ agaist the limit of 125 μg/m³. In 2023, no exceedances of the daily mean standard for sulphur dioxide in the ambient air of Dimitrovgrad were recorded.

RIEW - Haskovo carries out 24-hour monitoring of the combustion plant facilities through a thermal imaging camera positioned close to the plant. This monitoring enables a timely response by the regional inspection in case of irregularities at the production site of TPP Maritsa 3 AD.

In order to limit the accumulation of sulphur dioxide emissions into the air of Dimitrovgrad from TPP Maritsa 3 AD and the Maritsa East power complex, coordination and good communication has been established between the regional inspectorates in Haskovo and Stara Zagora for continuous monitoring of the sources of sulphur dioxide in order to take immediate measures to reduce the mass flow of this pollutant, if necessary, by all operators.