Ecomonitoring of sanitary protection zone of metallurgical enterprise: Snow and soil cover

Introduction

When evaluating the impact of large industrial enterprises, a crucial consideration involves mitigating the adverse effects on all environmental components. In resource-rich regions such as the Kemerovo Region (Kuzbass), both natural ecosystems and the urban environment, essential for ensuring the population’s quality of life, are significantly affected. This study focuses on eco-monitoring within the sanitary protection zone (SPZ) using JSC “EVRAZ United West Siberian Metallurgical Combine” (JSC EVRAZ ZSMK) as a case study. The enterprise in question is situated in close proximity to ten specially protected natural reserves (SPNR) of various levels and categories, notable heritage sites of Kuzbass. Distances to the boundaries of these SPNRs are as follows: 17 km – Uvaly Luchshego regional reserve; 30 km – Chernovoy Naryk regional reserve; 35 km – Kostenkovskie Rocks regional natural monument; 55 km – Kuzedeevsky regional natural monument; 55 km – Kuzedeevo Linden Island federal natural monument; 56 km – Kuznetsky Alatau state nature reserve; 65 km – Karakansky regional reserve; 68 km – Artyshta regional natural monument; 75 km – Belsinsky regional reserve; 83 km – Bochatskiye sopki regional reserve. Preserving these unique natural complexes necessitates compliance with environmental protection requirements, including the establishment of a sanitary protection zone. The primary goal of this zone is to reduce atmospheric air pollution levels to specified emission limits after the enterprises have implemented all necessary measures to eliminate harmful substances.

The objective of the paper is to investigate and analyze the impact of industrial emissions on the environmental status of soil and snow cover within the SPZ of JSC EVRAZ ZSMK.

Background

The set tasks to accomplish this objective were as follows:

– to explore the methods for investigating the soil-ecological condition within the sanitary protection zone;

– to analyze the findings derived from laboratory examinations of the snow cover and soil at the boundaries of the SPZ of JSC EVRAZ ZSMK.

Novokuznetsk is situated in the southern part of the Kemerovo Region within a vast depression amid the floodplains of the Kondoma and Tom’ Rivers. It is encircled by the Kuznetsk Alatau and Salair Ridge mountain ranges. The metallurgical plant of JSC EVRAZ ZSMK is situated in the northeastern region of the city. The rationale behind its location was to position the plant in close proximity to energy and raw material sources while maximizing the distance from residential areas within the city. JSC EVRAZ ZSMK falls into the category of first-class enterprises concerning plant capacity, process specifications, as well as the nature and volume of pollutants released into the environment. The sanitary protection zone’s radius for first-class metallurgical enterprises is typically 1 km (although in practice, it extends to 5 km), in accordance with SanPiN 2.2.1/2.1.1.1200 – 031 regulations. Landscaping involves the use of specialized tree species, constituting at least 50 % of the development footprint.

A modern metallurgical facility comprises various units that have the potential to emit pollutants into the surrounding air. Such emissions are virtually unavoidable. Hence, measures for safeguarding atmospheric air quality have been implemented, encompassing a system designed to ensure air purity and sustain it at levels safe for human life and health [1; 2].

The sanitary protection zone of JSC EVRAZ ZSMK comprises eight designated test sites within the northern industrial hub, each representing distinct soil types:

1 – floodplain granular soil near the Ilyinsky Bridge (east wind);

2 – alluvial meadow soil close to Teleuty Village (northeast wind);

3 – fertile leached chernozem behind Malaya Shchedrukha Village (north wind);

4 – leached chernozem in the area of Yubileynaya mine (north-west wind);

5 – meadow heavy loamy soil along the road to Kuregesh – Esaulovka (west wind);

6 – chernozem meadow heavy loamy soil near the road to Chistogorsk Settlement (south-western wind);

7 – leached moderately deep light loamy chernozem in the vicinity of Mokrousovo Village (south wind);

8 – leached moderately deep light loamy chernozem in the area of Ilyinka Village (southeast wind).

The Figure illustrates the respective areas of these test sites within JSC EVRAZ ZSMK.

The boundaries of the sanitary protection zone of the northern industrial hub extend at distances of 5 km to the north, 3.3 km to the northeast, 3.5 km to the east, 4.1 km to the southeast, 1.8 km to the southwest, 2.6 km to the west, 4 km to the northwest, and 4.2 km to the south from the boundaries of JSC EVRAZ ZSMK industrial site.

The assessment of environmental conditions in major cities and enterprises commonly involves individual environmental components: atmospheric air, surface and groundwater, soil (considering microflora), vegetation cover, and citizen health [3 – 7].

Snow cover, with its high sorption capacity, stands out as an informative indicator for detecting anthropogenic pollution not only in atmospheric precipitation but also in atmospheric air, subsequently affecting water bodies and soils [8].

Snow samples were collected following the guidelines of RD 52.04.186 – 89, utilizing a specific template (pipe) with a cross-sectional area of 50.3 cm², reaching from the top of the snow cover to the ground. These samples were then placed in plastic bags and transported to the laboratory for monitoring industrial waste, soils, fuels, and lubricants. In the laboratory, the samples underwent processing and analysis for pH, carbonate and bicarbonate content, chlorides, sulfates, dry residue, calcium, magnesium, and dust, in accordance with RD 52.04.186 – 89 procedures.

During the melting period, snowmelt enters water bodies and is categorized as atmospheric runoff2 [9 – 11]. To assess its condition, regulatory limits established in SanPiN1, 3, 4 were used as the basis of comparison. The findings of the snow water study are summarized in Table 1.

The data presented indicates that:

– dry residue in snowmelt water across all sites is (7 – 8 times) lower than the MPC;

– chloride ion content does not exceed the MPC (350 mg/l);

– sulfate ion content at site 1 is twice lower than the MPC, while at the other sites, it is below the detection limit outlined in RD 52.04.186 – 89 procedures;

– pH values at all sites fall within the normal range, confirming the absence of anthropogenic soil acidification within the SPZ territory.

Soil monitoring was conducted to oversee various soil parameters [12], encompassing data related to [13 – 15]:

– heavy metals such as vanadium, manganese, antimony, nickel, copper, zinc, lead, mercury, cadmium;

– arsenic;

– chemical indicators including pH (acidity), benz(a)-pyrene, petroleum products, and sulfur compounds.

Pollution indicators were assessed for eight chemical elements (V, Mn, As, Sb, Ni, Cu, Zn, Pb). Table 2 presents the specifics of soil contamination caused by heavy metals within the confines of the SPZ. The concentration of heavy metals and arsenic at the SPZ test sites remains below the MPC values.

The outcomes from chemical analyses of soils are outlined in Table 3. The active acidity (pH of the water extract) ranges between 6.30 and 7.40 units, signifying the absence of technogenic soil acidification. The petroleum product content (PNDF 16.1.41–04) observed in the selected soil samples remains below the threshold value (less than 20 mg/kg). Consequently, soils across all sites can be categorized as conditionally clean concerning this compound. Similarly, the concentration of benz(a)pyrene does not surpass the MPC values (0.02 mg/kg) at all test sites except for site 7. Additionally, the sulfur content (according to GOST 8606 – 93) does not exceed MPC values of 160 mg/kg.

To assess the degree of soil pollution, the technogenic concentration coefficient K_c is calculated [16]:

K_c = K_tot/K_bg,

where K_tot and K_bg are the element contents in the examined soil and in background soil, respectively.

When the soil is contaminated by two or more elements, the total pollution index Z_c is calculated as follows:

\[{Z_{\rm{c}}} = \sum\limits_{i = 1}^n {{K_{\rm{c}}} - (n - i)} ,\]

where K_c is the technogenic concentration coefficients that are greater than unity; n is the number of elements with K_c > 1.

The level of contamination is categorized as low if Z_c falls within the range of 0 – 16; medium (moderately hazardous) if Z_c = 16 ÷ 32; high (hazardous) if Z_c = 32 ÷ 128; very high (extremely hazardous) if Z_c > 128.

Table 4 presents the assessment of chemical pollution at the test sites for several elements. The evaluation outcomes can be summarized as follows:

– the total pollution index for sites 1, 2, 3, 6 is less than 16, indicating that soil pollution at these sites falls within the “acceptable” category;

– for sites 4, 5, 7, 8 the integral pollution index ranges between 16 and 32, classifying soil pollution at these sites as “moderately dangerous.

Conclusions

The analysis of snow cover revealed that the concentrations of heavy metals, including arsenic, dry residue in meltwater, chloride ions, and sulfate ions at the test sites within the SPZ of JSC EVRAZ ZSMK, do not surpass the MPC limits. Similarly, in the soil cover at these SPZ test sites, the levels of heavy metals (V, Mn, As, Sb, Ni, Cu, Zn, Pb), arsenic, sulfur, oil products, and pH values are within the normal range. The benz(a)pyrene level slightly exceeds the norm at only one out of the eight sites.

The total pollution index categorizes the contamination levels at four out of the eight test sites as “acceptable”.