3) Waste Water Collection Pipeline in Beichuan Zone
3.3 Current Environment Quality
3.3.2 Overview and Evaluation of Ambient Air (1) Overview of Quality of Ambient Air of Xining(1) Overview of Quality of Ambient Air of Xining
According to the Xining Environment Quality Bulletin (2011), there are now four ambient air automatic monitoring stations under national control in Xining to continuously carry out automatic monitoring of ambient air of the whole city. They include four monitoring points, i.e. city-level monitoring station, provincial medicine warehouse, Silu hospital and No. 5 Water Plant (control point of cleanliness).
The monitoring results indicate that the daily mean concentration of NO2 in urban area of Xining in 2011 was 0.026mg/m3 reaching the first-level standard (0.040mg/m3) in Ambient Air Quality Standard (GB3095-1996); that the daily mean concentration of SO2 is 0.043 mg/m3 reaching the national first-level standard (0.050mg/m3) for ambient quality. Compared with 2010, the concentration of oxynitride drops slightly and that of sulfur dioxide rises slightly; the daily mean concentration of inhalable particles (PM10) is 0.105 mg/m3, which drops slightly compared with 2010 and reaches the national third-level standard for ambient air quality (0.150mg/m3). In 2011, the total number of days monitored for ambient air quality of Xining was 365 days including 316 days with good ambient air quality. The rate of good air quality is 86.6%, up 1.4 percentage points compared with last year.
The primary pollutant that impacts the ambient air quality is still particles. In 2011, no acid rainfall occurred in Xining, and the annual average amount of dust fall of the whole city was 19.41t/km2 • month, which dropped slightly compared with 2010.
(2) On-line Monitoring Data of Xining Released by the Ministry of Environmental Protection
According to the real-time data for air quality of cities across China released by the website of the Ministry of Environmental Protection, four publishing points for monitoring data are set in Xining including provincial medicine warehouse, No. 5 water plant, city-level environment monitoring station and Silu hospital. The monitoring point of provincial medicine warehouse is located in the Chengbei District of Xining city. Fig 3.3-2-5 shows the data for SO2, NO2, PM10 and PM2.5 in one month continuously from September 25 to October 24. According to the data, the ambient air quality of Chengbei District is relatively good in general.
Figure 3.3-2 Daily Average Values of SO2 from September 25 to October 24
Figure 3.3-3 Daily Average Values of NO2 from September 25 to October 24
Figure 3.3-4 Daily Average Values of PM10 from September 25 to October 24
Figure 3.3-5 Daily Average Values of PM2.5 from September 25 to October 24
(3) Monitoring of Atmospheric Environment of Project Construction Area This environmental impact assessment covers monitoring of the atmospheric environment of project construction area and is mainly aimed at understanding the current quality of atmospheric environment of project construction area in Beichuan area and along the bank of Xichuan River. The monitoring scheme and results are as follows:
Monitoring point: See table 3.3-2 and Figure 3.3-1 for arrangement of monitoring points.
Monitoring factor: nitrogen dioxide, sulfur dioxide, TSP, ammonia and hydrogen sulfide.
Monitoring date and frequency: Monitoring is carried out at each sampling point synchronously with sampling and continuously for 7 days from August 8 to August 15, 2013.
For the daily average concentration of SO2 and NO2, continuous sampling time shall not be less than 18 hours;
For the daily average concentration of TSP, continuous sampling time every day shall not be less than 12 hours;
For hydrogen sulfide and ammonia, 4 times of monitoring are required at an interval of 2 hours, the maximal value is taken as the measurement result.
Table 3.3-2 Arrangement of Monitoring Points for Current Ambient Air Quality and Monitoring Results
SO2 NO2 TSP Ammonia Hydrogen
Sulfide
-August 9 0.057 0.035 0.316 0.199 0.008
August 10 0.03 0.026 0.5 0.175 0.009
August 11 0.037 0.027 0.36 0.151 0.005
August 12 0.044 0.028 0.341 0.168 0.008
August 13 0.04 0.031 0.19 0.192 0.009
August 14 0.033 0.04 0.213 0.176 0.008
August 15 - - - 0.169 0.008
-August 9 0.074 0.033 0.059 0.148 0.007
August 10 0.053 0.029 0.101 0.159 0.008
August 11 0.072 0.034 0.367 0.148 0.006
August 12 0.079 0.036 0.345 0.187 0.009
August 13 0.069 0.039 0.227 0.189 0.008
August 14 0.098 0.051 0.203 0.164 0.008
August 15 - - - 0.177 0.009
No.3 WWTP On 3-G1 Boundary of Plant
August 8 0.032 0.042 0.445 -
-August 9 0.015 0.042 0.697 0.489 0.077
August 10 0.021 0.04 0.536 0.144 0.003
August 11 0.018 0.033 0.524 0.185 0.009
August 12 0.023 0.052 0.404 0.459 0.006
August 13 0.022 0.047 0.302 0.467 0.003
On 2-G2 Boundary of Plant
August 8 0.038 0.035 0.297 -
-August 9 0.015 0.025 0.301 0.484 0.004
August 10 0.017 0.03 0.194 0.14 0.008
August 11 0.022 0.028 0.265 0.234 0.009
August 12 0.034 0.034 0.349 0.492 0.01
August 13 0.013 0.032 0.305 0.444 0.002
August 14 0.012 0.034 0.323 0.21 0.01
August 15 - - - 0.545 0.009
On 3-G3 Boundary of Plant
August 8 0.028 0.039 0.344 -
-August 9 0.006 0.03 0.39 0.52 0.006
August 10 0.008 0.028 0.195 0.395 0.005
August 11 0.03 0.029 0.288 0.43 0.008
August 12 0.027 0.038 0.286 0.444 0.007
August 13 0.032 0.039 0.309 0.456 0.006
August 14 0.02 0.031 0.266 0.429 0.011
August 15 - - - 0.472 0.007
On 3-G4 Boundary of Plant
August 8 0.029 0.036 0.289 -
-August 9 0.006 0.028 0.428 0.399 0.013
August 10 0.038 0.025 0.426 0.296 0.013
August 11 0.008 0.029 0.358 0.316 0.011
August 12 0.03 0.039 0.361 0.435 0.01
August 13 0.02 0.034 0.265 0.488 0.011
August 14 0.013 0.039 0.205 0.259 0.012
August 15 - - - 0.524 0.01
Class-II Standards for Quality Standard for
Ambient Air Environment（GB3095—2012） 0.15 0.08 0.3 -
-One-time Concentration limit of Sanitary Standard for Design of Industrial Enterprises
(Tj36-79)
- - - 0.2 0.01
Monitoring result and evaluation: The results indicate that the concentration of SO2, NOX and TSP in the ambient air of No. 4 and No. 5 WWTPs meets the limit value of Class-2 standard of Ambient Air Quality Standard (GB3095—2012), and that of H2S and NH3 meets the one-time limit value for concentration of Sanitary Standard for the Design of Industrial Enterprise (TJ36-79), which mean that the ambient air quality is good.
Xichuan wastewater interception main pipes connecting Duoba town with No. 4 WWTP is located in rural area, along the pipeline quality of acoustic environment is better than where the No. 4 WWTP is located. Therefore, acoustic environment along Xichuan River wastewater interception main pipes is good.
Since Beichuan River wastewater interception main pipes from Datong wastewater treatment plant to toll station of Xining-Datong Highway are to be installed in rural environment, the quality of acoustic environment is better than where the No. 5 wastewater treatment plant is located, thus acoustic environment along the Beichuan River wastewater interception main pipes is good.
(4) Investigation on Air Environmental Quality in Beichuan Area
To understand air environmental quality in Beichuan Area, data in EIA for Beichuan River Plan were referenced and the monitoring was conducted by Xining Environmental Monitoring Station in 2012, within the time inverval for data reference purpose.
Monitoring sites: 4 sites in total, located in Ershilipu Village, Shitoulei Village,
Biological Industry Zone and Qijiacheng, respectively.
Monitoring frequency: Monitoring was conducted for 7 consecutive days from Oct.24 to Oct.30, 2012, with daily value (at least sampling for 18 hrs a day), 1 hr average value (at least sampling for 45min.) of SO2, NO2 monitored at 6:00, 9:00, 14:00 and 18:00; daily average value of TSP (at least sampling for 12 hrs).
The monitoring results obtained are shown in the following table (Table 3.3-3).
Sites selected for the monitoring are shown in Figure 3.3-C.
Table 3.3-3 Monitoring Results of Ambient Air Quality (unit: mg/m3)
Locations
Concentration 0.020～0.085 0.006～0.096 0.004～0.109 0.015～0.094 Exceedance
Concentration 0.027～0.494 0.014～0.509 0.013～0.435 0.014～0.402 Exceedance
Concentration 0.030～0.049 0.027～0.047 0.023～0.052 0.019～0.049 Exceedance
Concentration 0.024～0.113 0.029～0.107 0.019～0.082 0.022～0.098 Exceedance
Concentration 0.302～1.301 0.378～1.214 0.203～0.327 0.367～1.049 Exceedance
Concentration 0.235～0.713 0.182～0.432 0.096～0.291 0.265～0.784 Exceedance
From the above table, it is clear that:
For SO2, its daily value of ranges from 0.004 to 0.096 mg/m3，hourly value ranges from 0.013 to 0.509 mg/m3，no exceedance of daily concentration was observed at all sites, except hourly concentration exceeding the standard at some individual site.
For NO2, daily value of ranges from0.010 to 0.029 mg/m3，hourly value ranges from0.013 to 0.509 mg/m3，no exceedance of daily or hourly concentration was found at all sites.
For TSP, daily concentration ranges from 0.203 to 1.301mg/m3，exceedance of daily concentration was observed at all sites, including 100% of exceedance ratio at Ershilipu Village, Shitoulei Village and Qijiacheng, 85% of exceedance ratio at Biological Industrial Zone, and the maximal times of exceedance reach 3.34.
For PM10, daily concentration ranges from 0.096 to 784mg/m3，exceedance of daily concentration was observed at all sites, and the exceedance ratio ranges from 85.7% to 100%, with maximal times of exceedance being 4.23 (at Site 4#).
Analysis of such monitoring results indicates that, since SO2 and NO2 in the assessment area are all within the standard scope, pollution by SO2 and NO2 is slight in the assessment area. TSP and inhalvable particulate matter exceeds the standard at all monitoring sites, while such exceedances are largely due to the geological location of the assessment area, because the project area is located in the northwest China, arid with little precipitation, and is prone to dust raised from the barren and dry cultivated land by winds.
3.3.3 Overview and Evaluation of Surface Water Environment