Prepared for. Samrand Development (Pty) Ltd JULY 2018

Transcription

1 AQUATIC WATER QUALITY BASELINE ASSESSMENT REPORT OF THE AQUATIC RESOURCES IN THE VICINITY OF THE PROPOSED KOSMOSDAL FILLING STATION PROJECT, KOSMOSDAL, GAUTENG. Prepared for Samrand Development (Pty) Ltd JULY 2018 Prepared by: Water Use Licence Associates (Pty) Ltd Report authors: Dionne Crafford (Pr. Sci. Nat.) Report reviewer: Stephen van Staden (Pr. Sci. Nat.) Report Reference: WUL Assessment Date: 25 May 2018 Report Initiation Date: 19 July 2018 Report Submission Date: 23 July 2018 Water Use Licence Associates (Pty) Ltd CK 2016/241418/07 Vat Reg. No Arterial Road West Oriel, Johannesburg 2007 Tel: Fax:

2 EXECUTIVE SUMMARY Water Use Licence Associates (Pty) Ltd (WULA) was requested by Samrand Development (Pty) Ltd to perform a water quality baseline assessment of the aquatic resources in the vicinity of the proposed Kosmosdal Filling Station. One site, considered to be representative of the aquatic resource at the time of assessment, was assessed on 25 May 2018 downgradient of the proposed development. In the Government gazette of 18 May 1984 No 9225 the general standard to which waste water and effluent must be purified prior to discharge is stated. The value for soap, oil and grease is 2.5 mg/l. With the promulgation of the new National Water Act in 1998 the strategy for conserving aquatic resources has changed, however, no new standard for soaps, oil and grease are available. The results of the water sampling at the downgradient site were thus compared to the available general effluent standard for comparison. Of the parameters assessed, dissolved lead, extractable petroleum hydrocarbons, gasoline range organics, methyl tert-butyl ether, benzene, toluene, ethylbenzene, m/p-xylene and o- Xylene presented with concentrations below detection, with the respective detection limits (<0.01 mg/l and lower) much lower than the recommended standard concentration (2.5 mg/l) mentioned above. These substances can thus be considered largely absent at the time of assessment. Oil and grease were also below detection (<50 mg/l), but the detection limit was much higher than the guideline recommendation. However, considering that all other hydrocarbon parameters were below detection, it can be assumed that oil and grease concentrations were also below 2.5 mg/l. Nitrate as NO 3 was detected, but at a concentration of 0.3 mg/l it complies with the recommended guideline recommendation. This baseline assessment indicates that, at the time of assessment, any significant potential impact on the aquatic resource from hydrocarbon pollution is considered unlikely. Using results from this assessment as baseline data, future monitoring of potential impacts from proposed Kosmosdal Filling Station development is possible. Potential future impacts from said development may include addition of chemicals related with fossil fuels (see parameters mentioned above) to the receiving aquatic environment due to accidental spillage and seepage from underground storage tanks. It is suggested that these parameters be monitored in future at the monitoring points upstream and downstream of the proposed fuel station, should the proposed development proceed, to monitor potential impact on the receiving aquatic environment. Data can be compared to the baseline data from this study to determine spatial variation form the baseline condition ii

3 TABLE OF CONTENTS EXECUTIVE SUMMARY... ii TABLE OF CONTENTS... iii LIST OF TABLES... iii LIST OF FIGURES... iii 1. INTRODUCTION Scope of Work Assumptions and Limitations METHOD OF INVESTIGATION PHOTOGRAPHIC SITE DOCUMENTATION WATER QUALITY RESULTS DISCUSSION CONSIDERATION OF CURRENT AND POTENTIAL FUTURE IMPACTS SYNOPSIS AND CONCLUSION REFERENCES LIST OF TABLES Table 1: Co-ordinates of the water sampling points... 2 Table 2: Water quality assessment results LIST OF FIGURES Figure 1: Downgradient water sampling assessment points presented on a digital satellite image Figure 2: a to 2e: Photographs showing conditions at the downgradient site... 7 iii

4 1. INTRODUCTION Water Use Licence Associates (Pty) Ltd (WULA) was appointed to conduct a baseline water quality assessment of the aquatic resources associated with the proposed Kosmosdal Filling Station development. The Kosmosdal Filling Station is situated immediately northeast of Samrand Avenue, and west of the M37 (Rooihuiskraal Road). The Summerfields Estate is situated immediately north of the Kosmosdal Filling Station. Furthermore, the Kosmosdal Filling Station is situated approximately 17km west of the N1 Highway, and 1.2km north of the Blue Valley Golf Estate. Automobile pollutants include substances such as oil, antifreeze, brake fluid, transmission fluid, grease and metals. Said substances that are spilled on hard surfaces may run off into stormdrains to subsequently pollute the receiving aquatic environment, or soak into groundwater (Hydro Flies Student Handout #1). These hydrocarbon substances are known to be detrimental to aquatic health (Hydro Flies Student Handout #1). Hydrocarbons have been shown to result in a decrease in the abundance of large zooplankton, protozoans, phytoplankton, microbial food benthic suspension and deposit feeding macrofauna and copepods (Fleeger et al 2003). In some marine oil spills, long-term organic enrichment resulted in organic enrichment and increased bacterial biomass of taxa that can exploit it, with resulting localised increase in benthic abundances (Fleeger et al. 2003). It must be noted that individual species can only metabolise a limited range of hydrocarbon substances, so generally a mixed population with overall broad enzymatic capacities are required to degrade complex mixtures of hydrocarbons (Leahy and Colwell 1990). Hydrocarbons may thus impact aquatic ecology either through direct negative effects, or through indirect bottom-up effects (via increased or decreased food supply). This is also evident when examining effects of total petroleum hydrocarbon in sediment on macroinvertebrates, with hydrocarbons at lower concentrations (860 mg/kg) increasing the abundance of some taxa but decreasing the abundance of others, whilst high concentrations (1858 to mg/kg) resulted in a reduction in the total number of taxa and their abundance (Pettigrove and Hoffmann 2005). In fish, oil exposure impairs cardio-respiratory responses and results in inability to meet the temperature-driven increase in tissues oxygen demand (Claireaux and Davoodi 2010). Direct effects of oil on forage fish also have a detrimental effect on birds and mammals that are dependent on them as food source, which is considered 1

5 another bottom-up effect (Fleeger et al. 2003). Negative effects of road traffic gases (including hydrocarbons) on plant growth have also been demonstrated (Spellerberg 1998). Hydrocarbons may also pollute sources of drinking water. It is estimated that oil from a single oil change can ruin 3.8 million litres of water, which translates to a year s supply for 50 people (Hydro Flies Student Handout #1). It is thus imperative that the potential future impact of the proposed Kosmosdal Filling Station be considered. In order to do so, relevant baseline conditions prior to implementation of the proposed development need to be established. This document presents the results obtained during the 25 May 2018 baseline water sampling occasion. Samples were submitted for analysis on 28 May 2018, and the laboratory report was issued 05 July Scope of Work The baseline assessment included collection of water samples at one site, considered to be representative of the aquatic resource at the time of assessment, downgradient of the proposed development. Selected water quality parameters related to hydrocarbons were assessed and compared to available guideline recommendations. This allowed evaluation of current potential impacts and will serve as baseline for future monitoring, should the proposed development proceed. Table 1 below contains geographic information for the monitoring point. Table 1: Co-ordinates of the water sampling points Site Description GPS co-ordinates South East Downgradient The site was selected as representative point downgradient of the proposed Kosmosdal Filling Station Development '25.67"S 28 7'53.72"E Figure 1 indicates the location of the water sampling point on a digital satellite image. 2

6 Figure 1: Downgradient water sampling assessment points presented on a digital satellite image. 3

7 1.2 Assumptions and Limitations The following points serve to indicate the assumptions and limitations with regard to this baseline assessment: Reference conditions are unknown: The state of water quality in the study area, prior to major disturbance, is unknown. As a result, conditions at the time of current assessment downgradient of the proposed development, will be considered as baseline for future monitoring comparisons. Temporal variability: The data presented in this report is based on a single site visit on 25 May The effects of seasonal and long-term variation on water quality at the site is unknown. However, it is the opinion of the aquatic ecologist that assessment of the point downgradient of the proposed development, provides adequate baseline data for use as reference in future monitoring occasions. However, it is recommended that an upgradient sampling point be added in future monitoring assessments to also allow spatial comparisons. 2. METHOD OF INVESTIGATION During the sampling occasion the following actions were performed: Visual conditions of each site were documented using photographs; Water samples were collected at each site and submitted to the Golder Associates Research Laboratory Pty Ltd. for analysis. Methods used for analysis were as per their laboratory Standard Operating Procedures. The following parameters were assessed: dissolved lead, extractable petroleum hydrocarbons (EPH), gasoline range organics (GRO), methyl tert-butyl ether (MTBE), benzene, toluene, ethylbenzene, m/p-xylene, o-xylene, oil and grease and nitrate as NO 3; The results of the water sampling at the downgradient site were compared to the available general effluent standard. In the Government gazette of 18 May 1984 No 9225 the general standard to which waste water and effluent must be purified prior to discharge is stated. The value for soap, oil and grease is 2.5 mg/l. With the promulgation of the new National Water Act in 1998 the strategy for conserving aquatic resources has changed, however, no new standard for soaps, oil and grease are available. 4

8 3. PHOTOGRAPHIC SITE DOCUMENTATION The following site photographs were taken at the sampling point (downgradient site), representing the surrounding area, flow and vegetation component. Figure 2a Figure 2b 5

9 Figure 2c Figure 2d 6

10 Figure 2e Figures 2a to 2e: Photographs showing conditions at the downgradient site 7

11 4. WATER QUALITY RESULTS The results of the water quality analysis are presented in Table 2. The following parameters were below detection: dissolved lead, extractable petroleum hydrocarbons, gasoline range organics, methyl tert-butyl ether, benzene, toluene, ethylbenzene, m/p-xylene, o-xylene, oil and grease. Nitrate as NO 3 was above detection. Table 2: Water quality assessment results. Parameter Downgradient point Value in mg/l Limit of detection (LOD) Dissolved Lead <0.005 <0.005 Extractable Petroleum Hydrocarbons (EPH) (C8-C40) <0.01 <0.01 Gasoline Range Organics (GRO) (>C4-C8) <0.01 <0.01 GRO (>C8-C12) <0.01 <0.01 GRO (>C4-C12) <0.01 <0.01 Methyl tert-butyl ether (MTBE) <0.005 <0.005 Benzene <0.005 <0.005 Toluene <0.005 <0.005 Ethylbenzene <0.005 <0.005 m/p-xylene <0.005 <0.005 o-xylene <0.005 <0.005 Nitrate as NO3 0.3 <0.2 Oil and Grease <50 <50 5. DISCUSSION Of the parameters assessed, dissolved lead, extractable petroleum hydrocarbons, gasoline range organics, methyl tert-butyl ether, benzene, toluene, ethylbenzene, m/p-xylene and o- Xylene presented with concentrations below detection, with the respective detection limits (<0.01 mg/l and lower) much lower than the recommended standard concentration (2.5 mg/l) mentioned above. These substances can thus be considered largely absent at the time of assessment. Oil and grease were also below detection (<50 mg/l), but the detection limit was much higher than the guideline recommendation. However, considering that all other hydrocarbon 8

12 parameters were below detection, it can be assumed that oil and grease concentrations were also below 2.5 mg/l. Nitrate as NO3 was detected, but at a concentration of 0.3 mg/l it complies with the recommended guideline recommendation. 6. CONSIDERATION OF CURRENT AND POTENTIAL FUTURE IMPACTS The proposed Kosmosdal Filling Station is located upgradient of the downgradient site. Current potential impact from anthropogenic activities includes run-off from hard road surfaces on which hydrocarbon spills may potentially occur, given vehicular use in the area. However, the baseline assessment indicates that current impact from hydrocarbon pollution in the study area is likely limited. Results presented in this report can be considered baseline values and allow for future monitoring of potential impacts from the proposed Kosmosdal Filling Station development. Potential future impacts from the Kosmosdal Filling Station may include addition of chemicals related with fossil fuels (see parameters mentioned in Table 2) to the receiving aquatic environment due to accidental spillages or leakage from underground storage tanks. It is suggested that the hydrocarbon parameters assessed in this study be monitored in future should the proposed development proceed, in order to monitor potential impact on the receiving aquatic environment. 7. SYNOPSIS AND CONCLUSION Water Use Licence Associates (Pty) Ltd (WULA) was requested by Samrand Development (Pty) Ltd to perform a water quality baseline assessment of the aquatic resources in the vicinity of the proposed Kosmosdal Filling Station. One site, considered to be representative of the aquatic resource at the time of assessment, was assessed on 25 May 2018 downgradient of the proposed development. 9

13 In the Government gazette of 18 May 1984 No 9225 the general standard to which waste water and effluent must be purified prior to discharge is stated. The value for soap, oil and grease is 2.5 mg/l. With the promulgation of the new National Water Act in 1998 the strategy for conserving aquatic resources has changed, however, no new standard for soaps, oil and grease are available. The results of the water sampling at the downgradient site were thus compared to the available general effluent standard for comparison. Of the parameters assessed, dissolved lead, extractable petroleum hydrocarbons, gasoline range organics, methyl tert-butyl ether, benzene, toluene, ethylbenzene, m/p-xylene and o- Xylene presented with concentrations below detection, with the respective detection limits (<0.01 mg/l and lower) much lower than the recommended standard concentration (2.5 mg/l) mentioned above. These substances can thus be considered largely absent at the time of assessment. Oil and grease were also below detection (<50 mg/l), but the detection limit was much higher than the guideline recommendation. However, considering that all other hydrocarbon parameters were below detection, it can be assumed that oil and grease concentrations were also below 2.5 mg/l. Nitrate as NO3 was detected, but at a concentration of 0.3 mg/l it complies with the recommended guideline recommendation. This baseline assessment indicates that, at the time of assessment, any significant potential impact on the aquatic resource from hydrocarbon pollution is considered unlikely. Using results from this assessment as baseline data, future monitoring of potential impacts from proposed Kosmosdal Filling Station development is possible. Potential future impacts from said development may include addition of chemicals related with fossil fuels (see parameters mentioned above) to the receiving aquatic environment due to accidental spillage and seepage from underground storage tanks. It is suggested that these parameters be monitored in future at the monitoring points upstream and downstream of the proposed fuel station, should the proposed development proceed, to monitor potential impact on the receiving aquatic environment. Data can be compared to the baseline data from this study to determine spatial variation form the baseline condition. 10

14 8. REFERENCES Claireaux G and Davoodi F Effect of exposure to petroleum hydrocarbons upon cardiorespiratory function in the common sole (Solea solea). Aquatic Toxicology 98(2): Fleeger JW, Carman KR and Nisbet RM Review: Indirect effects of contaminants in aquatic ecosystems. The Science of the Total Environment 317: Government Gazette No May Regulation No Requirement for the Purification of Waste Water or Effluent. Hydro Files. Land Use and Pollutants: Causes and Effects. Student Handout #1. Leahy GL and Colwell RR Microbial degradation of hydrocarbons in the environment. Microbiological Reviews 54(3): Pettigrove V and Hoffmann A Effects of long-chain hydrocarbon-polluted sediment on freshwater macroinvertebrates. Environmental Toxicology and Chemistry 24(10): Spellerberg IF Ecological effects of roads and traffic: A literature review. Global Ecology and Biogeography Letters 7(5):