5.2 Examples of Using the Standards

Figure 5.1 is a fictitious registration form for a fictitious bore located close to the geographical centre of Australia. The form contains the data about location, construction, water cuts and lithology that is typically documented upon registration of a bore.

Figure 5.2 remaps the data into the standard data model. The identification and owner details are described in the groundwater_feature entity. Being near the geographical centre of Australia, the borehole is also located in the Northern Territory. Hence, the letter ‘R’ is prefixed to the registration number as prescribed by Convention 4.1, to ensure uniqueness nationally. Upon registration at the Northern Territory Department of Lands, Planning and Environment (DLPE), the location of the borehole was transcribed onto the appropriate 1:100,000 scale topographic map, based on the lodged location sketch. The geographical coordinates for the bore were measured from the mapped position, and this data forms the basis of the site entity. Note the negative latitude value, indicative of locations south of the equator as is the case for Australia.

The elevation of the ground surface was also estimated from the topographic contours on the 1:100,000 scale map. This defines the first datum_plane for the feature. As the ground surface has been used since the beginning of construction as a reference point for data (eg. the lithology log and casing details) the establish_date is the start of construction. As we know the borehole is within the BEDDOME mapsheet, we have also defined our first locality. We also know that the bore is in the Northern Territory, so this becomes the second locality.

The construction details for the bore (the hole, casing, inlet and cementing) are all recorded as construction_elements and each assigned a unique construct_number. For presentation purposes, and since all of the bore was constructed by the same person, common attributes such as person, license and organisation are represented once as header information rather than replicated in each record. All of the construction_elements have a circular cross section so the minimum_dimension and maximum_dimension are identical, and in this case, describe outside diameter (external) measurements. As the inlet (element 5) was constructed by the slotting of the 140mm ABS casing (element 4), its precursor_number attribute has a value of ‘4’. The inlet also has specific properties such as slot length, slot aperture and slot density. These are defined separately as construction_element_properties, along with the fact that mud was the fluid used in drilling.

The details of the bore development are described as a construction_activity. Note the days:hours:minutes:seconds format for the 1.5 hour duration of the backwashing. The fact that the borehole was intended to be used for a domestic water supply is documented as a purpose-type status.

Three distinct groundwater_sources can be assigned to the bore, namely the initial water cut at 70 metres that proved too saline, the initial intersection of the good water at 226 metres during drilling, and the final constructed inlet between 225-238 metres. Each of these sources is uniquely defined by their source_number, so that any observations or measurements can be referred specifically back to them.

The drilling and construction of the bore is treated as a single event for the purposes of data collection. During this event, measurements and observations were made on four insitu samples – the three groundwater_sources as well as the geological profile from ground surface to a depth of 240 metres. These samples are assigned a unique sample_number with respect to this event for this particular bore. How these samples relate to the groundwater_sources is defined by the source_number, while the datum_number value of ‘1’ indicates that all depth measurements are relative to ground surface.

The types of measurements and observations that were taken during this drilling and construction event are described as parameters, and assigned a parameter_number. In this case, hydrogeological parameters such as the standing water level, draw down, pumping rate and salinity were described. The actual measurements and observations are recorded as results, with each assigned a unique result_number.

Each result relates to a particular sample and a particular parameter. Hence the first set of results are the lithological description (parameter_number = 1) for the geological profile from ground surface to 240 metres depth (sample_number = 1). The lithological log can be viewed in two different ways, firstly as a lithological description in a text string, or in terms of its components such as rock type, colour, texture, composition and grain size.

In the second result table, the lithological description has been disaggregated into the separate descriptors. This gives greater power and flexibility in querying the data. The concept of fractions is also used. For example, the lithology for the 27-60 metre interval has been defined as two fractions, a ‘blue-grey and brown shale’ part and a ‘brown puggy clay’ part, and described accordingly. Note also the combining of codes used to describe parameters such as colour and grainsize, referring to Convention 4.8. The ‘-’ join is used to describe a transitional or merging situation (eg. ‘BL-GY’ to describe the colour blue-grey, ‘MS-CS’ for a grainsize distribution ranging from medium to coarse) while the ‘+’ join is used when separate and distinct populations are found (eg. ‘BL-GY+BR’ for a separate blue-grey colour and a separate brown colour).

Some conversion of data was required for the airlift test data. The value of 1.5 for result 11 is because drawdown is defined as the change in water level rather than the final water level depth as noted on the form. A positive value is used to report a lowering of levels, in reference to Convention 4.2. The recorded yield or discharge rate during pumping had to be converted from gallons per hour into the standard units of litres/second. Multiplication factors are available within the standards for such unit conversions.

A few months after construction of the Centric Australis bore, it was visited by a hydrogeologist from the Northern Territory Department of Lands, Planning and Environment. This visit was part of a bore census of the area undertaken to collect field data to assist in the compilation of the FINKE 1:250,000 scale hydrogeological map. Based on his field measurements and observations as well as discussions with the bore owner, additional information about the bore was obtained from the on-site visit on the 20^th August, 1998. This included:

1. The bore has been operating since construction, having been equipped with a submersible pump and used sporadically for providing water to the homestead and garden.
2. A concrete base had been constructed by the owner around the bore to protect it from erosion.
3. The water level was measured at about 10 am to be 14.2 metres from the top of the casing using an electric-contact type tape.
4. After pumping from the bore, a groundwater sample was taken at about 1 pm, filtered and bottled for dispatch to an analytical laboratory. Routine field parameters like pH, temperature and EC were measured.
5. The bore is located on a gently sloping terraced flat associated with the Finke River.
6. The geographical position and elevation of the bore were measured using a differential GPS.

Figure 5.3 is the analytical report for the groundwater sample received back from the laboratory. Figure 5.4 collates all of the information relevant to the visit, including the chemistry results, using the standard data model.

Of significance is the update to the geographical coordinates for the site of the bore. As a groundwater feature has only one site by definition, the more accurate GPS-derived coordinates replace the previous coordinates estimated from the 1:100,000 scale topographic map. This update also occurs for the elevation measurement of the ground surface (datum_plane = 1). In addition, the top of the casing, which is 0.3 metres above the ground surface, has also been established as a datum_plane, recognising that post-construction ground water level measurements use it as a point of origin.

The new additions to the bore (the concrete base and the submersible pump) are defined as additional construction_elements. The facts that the bore is operational and used for the purpose of domestic/garden supply are defined as statuses. The location of the bore on a gently sloping terraced flat is represented in the slope-type and landform-type settings.

The field inspection becomes the second data collection event for the bore. At about 10 am, the groundwater level in the bore was measured. The insitu sample (sample_number = 1) is the groundwater within the bore casing derived from the constructed inlet (source_number = 3), with the top of the casing used as a reference of measurement (datum_number = 2). The second sample (sample_number = 2) relates to the actual discrete sample of groundwater removed at about 1 pm following pumping by the installed submersible. This sample was filtered and bottled in preparation for the laboratory. Details about this regular sample are defined as sample_properties, and include its field identifier, the name and address of the laboratory, when the lab received it, and when the analysis was completed.

The parameters are mostly the chemical analytes measured in the laboratory but also include the field parameters such as standing water level, EC, pH and temperature. Note that there are two parameters that deal with electrical conductivity – one was the field probe and the other was the more accurate platinum electrode conductivity cell used in the laboratory. In this case, the calculated parameters such as hardness and ion ratios are not included in the transfer, as they can be easily derived from the laboratory measurements. The units of measurement as defined by the data standards are used. Note that the cations were determined by an inductively coupled plasma atomic emission spectrophotometer, the alkalinity by titration, and the anions by a combination of ion selective electrodes and ion exchange chromatography. The total dissolved solids was derived gravimetrically after drying in an oven at 180 degrees Celsius.

Again, the results are mapped to a sample and a parameter relevant to the event and groundwater_feature. In this situation where there is only one result for each parameter, it is easy to integrate these tables together for ease of presentation. The field parameters such as temperature and pH were taken before filtration so they apply to the groundwater sample in total (fraction_type = TOT), while the laboratory parameters apply to the filtered or soluble fraction of the sample (fraction_type = SOL).

Fig 5.1 Worked example – Registered particulars of completed bore

Fig 5.1b Worked example - registered particulars of completed bore

Fig 5.2 Worked example – Construction data using standard data model

Fig 5.3 Worked example – Laboratory report on chemical analysis

Fig 5.4 Worked example – Field reconnaissance data using standard data model