preliminary soil salinity assessment - Mid Western Regional Council

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TABLE 2: MONTHLY RAINFALL RECORDS, MUDGEE NSWMonthlyRainfallReceived(mm)AverageMonthlyRainfall(mm)May June July Aug Sept Oct Nov Dec Jan Feb Mar April TOTAL2011 2011 2011 2011 2011 2011 2011 2011 2012 2012 2012 201250.2 16.4 9.6 67.0 86.0 53.4 127.6 65.2 55.2 145.0 137.2 12.2* 82549.4 54.6 52.9 53.4 52.0 60.3 62.3 65.3 67.5 64.1 51.1 44.2 677.1* Record for nearby station Mudgee, Airport AWS as data unavailable for Mudgee, George St.Source: Bureau of Meterology, http://www.bom.gov.au/jsp/ncc/cdio/weatherData2.3 Site Location and Land UseThe subject site, as detailed in Appendix A: Location Map, has a total land area of 5.665 hectaresand is located approximately 1.5km west of Mudgee. The land is intersected by Saleyards Lane withLot 2 in DP 534336 (1.214ha) located on the northern side of the lane, and Lot 399 in DP 1132580(2.428ha), and Lot 532 in DP 1132581 (2.023ha) on the southern side.Livestock sales were conducted at the saleyards constructed on the site from the 1880’s. Cattle weresold from these saleyards until 1994 and sheep until 2003. Pigs were also sold at the saleyards ataround this time. The land is now used for low intensity cattle grazing and storage of councilroadwork materials.Most records for the site were lost during a fire at the council’s offices in the 1980’s howeverdocuments obtained from the council dating post fire, in addition to personal comms with a localequipment hire company contracted to carry out maintenance work at the saleyards in the 1980’sand 1990’s (Mr Colin Box, C & M Box Hire) have provided an indication of the site layout andinfrastructure supporting the saleyard facility. This information has been used to gain someunderstanding of soil profile disturbance and previous land use likely to impact on the currentsalinity status of the site.Livestock were held frequently at sale time for short periods on Lot 399 in DP 1132580 and Lot 532in DP 1132581. The lower slopes on these two parcels of land were used for selling pens. Cattleyards were constructed along the south eastern side of the site. These were gravel lined and notsealed. It is understood that sheep yards were constructed along the lower slopes facing SaleyardLane with gravel lining. A pig shed with concrete flooring was located in the northwestern corner ofthis area.Further upslope to the top of the small hill on the south west of the subject land were variousholding yards which are believed to have been unlined. The relatively steep slope of the site wasused to facilitate drainage for the saleyards. It is understood that run-off from the selling pens andholding yards flowed downslope to the adjacent waterway south east of the site and across SaleyardLane to leachate ponds constructed within DP 534336.Remnants of the old saleyards still remain including a section of yard fence along the south easternside of the site and piles of materials previously part of the fencing and watering system that havebeen pulled down. All concrete flooring has been removed on the southern side of Saleyards Land. A6PRELIMINARY SOIL SALINITY ASSESSMENT
number of piles of material containing soil, concrete, gravel and some fencing materials exist on thesite particularly on the lower slopes. It appears the site was graded after the pens and yards wereremoved however no information was found by council to confirm this observation.A brick building still exists on DP 534336 which was associated with the old saleyards and lateroccupied by the State Emergency Service. West of this building remains a concrete pad that waspreviously used as a truck washdown facility. Dirty water from this washdown facility is believed tohave been directed to the nearby leachate ponds.At the initial site investigation and soil testing on 15 th May 2012 DP 534336 also contained a numberof piles of materials used for road construction by Mid-Western Regional Council. These occupied alarge area of this parcel of land. A small area to the north west of DP534336 appears to be relativelyundisturbed, which was confirmed anecdotally by Mr Colin Box.The land has been cleared almost entirely with a small number of eucalypt trees retained on the hillin the south western corner of the site and other scattered trees that appear to have been plantedfor shade. Groundcover across the site consists of a variety of grass and weed species. The hill areahas a mixture of perennial native grass species, while the lower slopes are dominated by couch grass(Cynodon dactylon) and kikuyu (Pennisetum clandestinum).The previous land use at this site raises particular concerns regarding soil salinity. Animal waste(faeces and urine) contains salt, including sodium salt. The intensive animal stocking at saleyardsresults in a concentration of animal waste with a relatively high level of salt that can potentiallyaccumulate at the site or enter the environment from the site. The amount of salt to enter the soiland waterways, and the impact of this salt on the environment, will depend on a range of factorssuch as:Design of animal holding facilities including the floor material and compaction of the pensand yards, and slope of earthern floored facilities,Animal waste collection, storage and disposal system design,Design of dirty water management system including containment and disposal,Rainfall,Soil profile characteristics within and surrounding the facilities, andNatural ground and surface water systems.From the limited information available on the now removed saleyard facilities and wastemanagement at the site, it is likely that some leaching of salts may have occurred into the soil profileacross the site. The relatively steep slope of some of the land south of Saleyards Lane (depicted inAppendix B: Current Site Layout, Topography and Soil Pit Locations is likely to have assisted inminimising leaching of salts into the soil profile on these sloped areas where some of the pens andyards were located.However, on the lower slopes and across Saleyards Lane where it is understood dirty water wasdirected to the leachate ponds and low lying areas, leaching of salts into the profile have occurred.As salts dissolve in soil water and are mobile in soil, rainfall across the site since the saleyards wereremoved is likely to have led to leaching of salts through the soil profile or into groundwater and isPRELIMINARY SOIL SALINITY ASSESSMENT7
Page 2 and 3: This report has been prepared byCon
Page 4 and 5: Table of TablesTable 1: Summary of
Page 6 and 7: Source: NSW Department of Primary I
Page 8 and 9: egional processes”. Existing and
Page 12 and 13: likely to have reduced the concentr
Page 14 and 15: drainage in the floor of the livest
Page 16 and 17: Plate 5: Soil profile at Site 5 soi
Page 18 and 19: TABLE 3: DOMINANT GROUND COVER SPEC
Page 20 and 21: 2.6.3 Soil Sampling for Laboratory
Page 22 and 23: Table 12: ECe Values of Soil Salini
Page 24 and 25: 3 SITE INVESTIGATION RESULTS AND DI
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Page 28 and 29: As discussed previously (Section 3.
Page 30 and 31: 4. Consider drainage with adequate
Page 32 and 33: Appendix ALocation MapThe land subj
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Page 40 and 41: Appendix CLaboratory Certificate of
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