**6. The status of the wastewater**

Insufficiently purified or even not at all purified wastewater discharge is one of the main causes of pollution and degradation of surface waters. Therefore, the main practical measures for the protection of the quality of surface waters is the purification of wastewater, which is collected and processed by a sewage system by sewage station, from where, as a rule, then are returned to the emissary.

The largest volumes of not purified and/or insufficiently purified wastewater resulted from units of the communal areas: households, heat and power plants, chemical processing, and then smaller volumes from units in the areas of trade and services for the population and from the extractive industry. Related to potential pollution, the highest share belongs to the fields of communal enterprises, and thermal electricity industry, extractive industry followed by businesses in the chemical industry, metallurgical, etc.

In 2005, the results of the monitoring activity performed on the main sources of wastewater, revealed the following realities: toward a total volume of the evacuated 3,886.126 million m3/year, 1,944.389 million m3/year, meaning 50.03%, is part of the waste water to be purified. Of the total volume of wastewater requiring treatment, 1,944.389 million m3/year, respectively, a volume of 351.400 million m3/year, (18.07%), was sufficiently purified (as scheduled). Otherwise 660.634 million m3/year, (about 34.9%), are not purified wastewater, and 848.482 million m3/year, about 44.9%, not completely purified wastewater. So, in 2006, about 79.8% of not or insufficiently purified wastewaters from the main sources of pollution, have reached the natural receptors, especially rivers. Compared with the total number of 1,035 investigated purification stations, installations, only 274 stations, representing 26.5%, have functioned properly, and the rest of 761 (73.5%) operated improperly.

The statistical analysis of the main sources of wastewater, according to the results of the monitoring activity carried out in 2006, revealed the following global issues: toward a total volume of the evacuated 3,586.126 million m3/year, 1,891.622 million m3/year, meaning 52,7%, is part of the waste water to be purified. Of the total volume of wastewater requiring treatment, 1,891.622 million m3/year, respectively, a volume of 382.506 million m3/year, (20.2%), was sufficiently purified (as scheduled). Otherwise 660.634 million m3/year, (about 34.9%), are not purified wastewater, and 848.482 million m3/year, about 44.9%, not completely purified wastewater. So, in 2006, about 79.8% of not or insufficiently purified wastewaters from the main sources of pollution, have reached the natural receptors, especially rivers. Compared with the total number of 1,035 investigated purification stations, only 274 stations, representing 26.5%, have functioned properly, and the rest of 761 (73.5%) operated improperly.

The statistical analysis of the main sources of wastewater, according to the results of the monitoring activity carried out in 2007, revealed the following global issues: toward a total volume of the evacuated 4,985..065 million m3/year, 2,210.285 million m3/year, meaning 44.30%, is part of the waste water to be 498.668.506 million m3/year, (22.60%), was sufficiently purified (as scheduled). Otherwise 791.320 million m3/year, (about 35.80%), are

assessment of groundwater bodies, the situation of those qualitative 142 bodies of groundwater shall be presented as follows: 109 bodies are in a good quality, 22 of groundwater bodies are in a poor quality, while 11 groundwater bodies are in a poor

Insufficiently purified or even not at all purified wastewater discharge is one of the main causes of pollution and degradation of surface waters. Therefore, the main practical measures for the protection of the quality of surface waters is the purification of wastewater, which is collected and processed by a sewage system by sewage station, from where, as a

The largest volumes of not purified and/or insufficiently purified wastewater resulted from units of the communal areas: households, heat and power plants, chemical processing, and then smaller volumes from units in the areas of trade and services for the population and from the extractive industry. Related to potential pollution, the highest share belongs to the fields of communal enterprises, and thermal electricity industry, extractive industry

In 2005, the results of the monitoring activity performed on the main sources of wastewater, revealed the following realities: toward a total volume of the evacuated 3,886.126 million m3/year, 1,944.389 million m3/year, meaning 50.03%, is part of the waste water to be purified. Of the total volume of wastewater requiring treatment, 1,944.389 million m3/year, respectively, a volume of 351.400 million m3/year, (18.07%), was sufficiently purified (as scheduled). Otherwise 660.634 million m3/year, (about 34.9%), are not purified wastewater, and 848.482 million m3/year, about 44.9%, not completely purified wastewater. So, in 2006, about 79.8% of not or insufficiently purified wastewaters from the main sources of pollution, have reached the natural receptors, especially rivers. Compared with the total number of 1,035 investigated purification stations, installations, only 274 stations, representing 26.5%,

The statistical analysis of the main sources of wastewater, according to the results of the monitoring activity carried out in 2006, revealed the following global issues: toward a total volume of the evacuated 3,586.126 million m3/year, 1,891.622 million m3/year, meaning 52,7%, is part of the waste water to be purified. Of the total volume of wastewater requiring treatment, 1,891.622 million m3/year, respectively, a volume of 382.506 million m3/year, (20.2%), was sufficiently purified (as scheduled). Otherwise 660.634 million m3/year, (about 34.9%), are not purified wastewater, and 848.482 million m3/year, about 44.9%, not completely purified wastewater. So, in 2006, about 79.8% of not or insufficiently purified wastewaters from the main sources of pollution, have reached the natural receptors, especially rivers. Compared with the total number of 1,035 investigated purification stations, only 274 stations, representing 26.5%, have functioned properly, and the rest of 761

The statistical analysis of the main sources of wastewater, according to the results of the monitoring activity carried out in 2007, revealed the following global issues: toward a total volume of the evacuated 4,985..065 million m3/year, 2,210.285 million m3/year, meaning 44.30%, is part of the waste water to be 498.668.506 million m3/year, (22.60%), was sufficiently purified (as scheduled). Otherwise 791.320 million m3/year, (about 35.80%), are

followed by businesses in the chemical industry, metallurgical, etc.

have functioned properly, and the rest of 761 (73.5%) operated improperly.

quality, locally.

**6. The status of the wastewater** 

rule, then are returned to the emissary.

(73.5%) operated improperly.

not purified wastewater, and 919.083 million m3/year, about 41.60%, not completely purified wastewater. So, in 2007, about 77.40% of not or insufficiently purified wastewaters from the main sources of pollution, have reached the natural receptors, especially rivers. Compared with the total number of 1,348 investigated purification stations, only 410 stations, representing 30.40%, have functioned properly. The remaining 938 stations (69.60%) operated improperly, because of not enough treatment capacity, or due to the operating and maintenance problems (advanced physical and moral wear inefficiency of the biological treatment phase concerning the insurance of needed oxygen, lack of investments for modernization, etc).

Fig. 8. The evolution of the wastewater categories during studied period of 5 years 2005 – 2009. I – water resulted from purification stations that functioned properly; II – wastewater to be purified; III – wastewater sufficiently purified (corresponding); IV – wastewater insufficiently purified; V – wastewater not purified

Compared with the total refused volume 5,254.565 million m3/year, 1,868.832 million m3/year (35.57% of the total) were wastewater to be purified. Of these, 560.623 million m3/year (30%) were sufficiently purified (corresponding), 689.145 million m3/year (36,87%) have been insufficiently purified wastewater and 619.064 million m3/year (33.13%) were not purified wastewater. Therefore, in 2008, a rate of 70% of wastewaters, not purified or insufficiently purified, from the main sources of pollution, has reached the natural receptors, especially rivers.

Statistical analysis of the situation of the main sources of waste water, according to the results of the monitoring carried out in 2009, revealed the global issues that are described below. Compared with the total volume of the refused water - 5,206.207 million m3/year, 2,058.899 millions m3/year (39.6% of the total) are wastewater to be purified. Of these, 485.438 million m3/year (23.60%) were sufficiently purified (corresponding), 909.019 millions m3/year (44.2%) were insufficiently purified wastewater and 664.442 million m3/year (32.2%) were not purified wastewater. Therefore, in 2009, 76.5% of not purified or insufficiently purified wastewaters from the main sources of pollution have reached the natural receptors, especially rivers. Compared with the total number of 1.363 investigated (urban and industrial) purification stations, only 445 stations, accounting for 33%, have functioned properly, and the remaining 9 stations, namely 67% operated improperly.

Evolution of Water Quality in Romania 147

The correlation coefficients emphasized between Cu, Cd, Mg, and Zn pollutants in surface water by 2008 (Table 4), were positive very strong (0.861 – 0.918) and very significant (P < 0.001). The calculated average value of the determination coefficient justifies 88.60% the

Similarly with previous years of analyzed period of five years (2005 – 2009), the calculated correlations between the main metallic pollutants (Cu, Cd, Mg, and Zn) of the surface water in the last year of the studied interval of time, 2009, respectively (Table 5), revealed very strong (0.868 – 0.908) and very significant values (P < 0.001). The average value of the

Issue Cu (mg/L) Cd (mg/L) Mg (mg/L) Zn (mg/L) Cu (mg/L) 1.000 0.861\*\*\* 0.899\*\*\* 0.869\*\*\* Cd (mg/L) 1.000 0.875\*\*\* 0.918\*\*\* Mg (mg/L) 1.000 0.895\*\*\* Zn (mg/L) 1.000

Table 4. The correlation matrix\* for main pollutant components of surface water data, in 2008

Issue Cu (mg/L) Cd (mg/L) Mg (mg/L) Zn (mg/L) Cu (mg/L) 1.000 0.899\*\*\* 0.898\*\*\* 0.868\*\*\* Cd (mg/L) 1.000 0.893\*\*\* 0.908\*\*\* Mg (mg/L) 1.000 0.875\*\*\* Zn (mg/L) 1.000

Table 5. The correlation matrix\*between main pollutant components of surface water in 2009

In groundwater, by 2005 (Table 6), very strong positive correlations, statistically very significant (P < 0.001) were identified between phosphates and nitrogen compounds (0.905; R2 = 0.819), and also between Cl, S, Pb, Cd, Hg, As, oil products, pesticides (0.922 – 0.793), with an average R2 = 0.797. Weak positive correlations, statistically not significant (P > 0.05) were identified between Cd, As, oil products, pesticides and phosphates, and also between Cl, S, Pb, Cd, Hg, As, oil products, pesticides and nitrogen compounds (Table 6). Average positive correlations were calculated between Cl and nitrogen compounds, statistically distinct significant (P < 0.01), and significant (P < 0.05) for S, Pb, Hg and nitrogen compounds,

In 2006 (Table 7), too, very strong positive correlations, statistically very significant (P < 0.001) were identified between phosphates and nitrogen compounds identified in groundwater (0.912; R2 = 0.831), and between Cl, S, Pb, Cd, Hg, As, oil products, pesticides (0.923 – 0.791), with an average R2 = 0.821. Weak positive correlations, statistically not significant (P > 0.05) were identified between Cl, S, Pb, Cd, Hg, As, oil products, pesticides and phosphates (0.195 – 0.439), and also between S, Cd, Hg, As, oil products, pesticides and nitrogen compounds (0.354 – 0.498) while between Cl and nitrogen compounds was identified a positive (0.528) statistically significant moderate correlation (P < 0.05), and between Pb and nitrogen a statistically distinct significant (P < 0.01) moderate correlation coefficient of 0.583 (Table 7).

**7.2 Correlations between main pollutants of groundwater** 

determination coefficient, 89.00% of our data conform to the linear relationship.

conformity of our data with the linear relationship.

\*R2 = 0.886

\*R2 = 0.890

respectively (Table 6).
