Projects undertaken by Earthwise Environmental Consultants (EEC)

Brief: Provide advice for a new commercial on-site wastewater management system (OWMS)  for a factory located in a rural area.

Problem: The old OWMS  was unable to dispose of the treated wastewater fast enough and as a result treated effluent was pooling on the surface. 

Challenge: The factory had approximately  80 employees and was growing in numbers. There was little room to dispose of the effluent. 

Action: Earthwise Environmental Consultants (EEC) undertook a site investigation to identify an area for effluent disposal. The soil investigation found  the soil texture to consist of heavy clay which results in very slow  infiltration rates meaning a very large area would be needs to dispose of the effluent. 

Outcome: EEC worked with client and septic tank manufacturer to build an advanced Aerated Wastewater Treatment System (AWTS) allowing for a reduced irrigation area plus recommended an effluent disposal method allowing for greater water losses via seepage and evapotranspiration plus permitting a beneficial re-use of the water.

Brief: Create a Remedial Action Plan (RAP) outlining how to rehabilitate a heavily contaminated site to ensure public safety. 

Problem: The closure of the oyster industry in the 1970s left the Woolooware Bay foreshore in a state of decay. Testing of the soils along the shoreline found concentrations of Polycyclic aromatic hydrocarbons (PAHs) which exceeded Health Investigation Levels (HIL). Sutherland Shire Council wanted to finalise the missing link of the Woolooware shared recreational pathway however needed to ensure the heavily contaminated shoreline was  remediated so that it would pose little threat to the general community. 

Action: Earthwise Environmental Consultants(EEC) met with Sutherland Shire Council staff to listen to their needs and then devised a Remedial Action Plan that would ensure public safety plus allow the degraded shoreline to be rehabilitated. 

Outcome:

EEC’s advice and recommendations has allowed the competition of the Woolooware shared pathway and has transformed the heavily polluted shoreline into one of Sydney’s most scenic foreshore reserves. 

Brief: Undertake testing of in-situ soils to classify them in accordance with the Excavated Natural Material Order (2014) and NSW EPA Waste Classification guidelines.

Problem: Rural areas with a history of agriculture can potentially be contaminated and as a result any soil leaving the site could create contamination to the receiving site. The Protection of the Environment Operations Act 1997 (POEO Act) and the Protection of the Environment Operations (Waste) Regulation 2005 control all activities that might harm our environment and prohibit how certain materials can be recycled.

Challenge: Earthwise Environmental Consultants (EEC) needed to determine whether large volumes of soil to be excavated from the site were free from contamination so that the material could be safely reused at another site. Council needed the work completed in a short time frame as construction was to commence shortly.

Action: EEC immediately undertook sampling of the in-soil and sent it for laboratory testing. 

Outcome: EEC did not find any contaminants of concern and were able to classify the soils within the proposed excavation corridor as Virgin Excavated Natural Material (VENM). The client was able to find a recipient for the VENM material (saving it from going to landfill) and both parties were able to comply with their respective legislative requirements. In the end the material was beneficially reused.

Brief: EEC was approached by local council to undertake a series of separate Review of Environmental Factor (REF) studies for several proposed flood mitigation works on various creeks/drains in northern Illawarra which had been identified as having issues related to erosion or flooding. 

Problem: Under Part 5 of the Environmental Planning & Assessment Act (EP&A) council must satisfy sections 5.5 and 5.7 of that Act by examining and considering to the fullest extent possible, all matters which are likely to affect the environment. 

Challenge: ECC needed to ensure council complied with the EP&A Act by identifying any legislative or environmental considerations needed before works begin.

Action: Undertake site inspection to identify potential issues associated with proposed works. Undertake desktop review of online databases (e.g. endangered flora and fauna lists, heritage sites,  undertake Due Diligence assessment of potential impacts on Aboriginal objects). 

Outcome: Earthwise Environmental Consultants (EEC) was able to ensure that council complied with the EP&A Act by identifying any legislative or environmental considerations needed before works begin, plus, provide a list of recommendations that council could easily implement  to minimize environmental harm, leading to positive environmental outcomes.

Brief: Undertake Stage 2 - Detailed Site Investigation  for land identified during a Stage 1 Preliminary Site Investigation (PSI) as being potentially contaminated with asbestos, PAH's and metals. 

Problem: The land had previously been zoned “industrial” and was part of an old coal mine site. After the land was rezoned to residential, previous land owners started to dump items such as old cars on the site. Historic photos also revealed an fibro shack was also build on the site which potentially contained asbestos. Potential Contaminates of Concern (CoC’s) identified included asbestos, heavy metals and poly aromatic hydrocarbons (PAHs).

Challenge: Identify the depth of the fill at the site and gather enough information to be able to able to accurately characterise the site.  

Action: EEC dug several test pits to screen for asbestos while also undertake several cores across the site to determine the depth of fill. Compile comprehensive Stage 2 detailed site investigation report

Outcome: ECC found one soil sample containing lead concentrations exceeding the National Environment Protection Measure Health Investigation Level (HIL) of 300 mg/kg. EEC was able to conclude that the source of lead was likely to be from the previous house on-site as the location matched the footprint of the house. EEC was able recommend a solution that would safely allow the proposed dwelling to proceed with minimal impact to human health. As a result of EEC’s thorough investigation, the client was given approval to construct a new house. 

Brief: Undertake an Acid Sulfate Soil (ASS) investigation to determine whether actual acid or potential ASS were present at the low lying coastal site. 

Problem: It could not be determined whether soil at the site contained reduced inorganic sulfur (i.e. acid sulfate soils) as there was large gaps in data.

Action:  EEC undertook fresh site and soil investigations and followed a different testing methodology . 

Outcome:  EEC was able to conclude that there was no  iron sulfide minerals (pyrite) at the site capable of oxidizing under aerobic conditions. Therefore an ASS management plan was not required.