preparing a site for installation of high pressured system

The ditch witch digging a trench for the irrigation pipe to lay down in.

Laying pipe down in a bed of sand. Wiring being taped underneath to prevent damage if pipe needs to be excavated.

Back filling with sand and then the excavated soil.

A schematic diagram of the circuit.

Positioning the solenoids to be connected to the control box at a later date.

Trench for a line along the production beds.

marking out the site for solenoid boxes.

isolating and marking out trenches and excavated holes to prevent injury, redirecting traffic along safer routes, restricting general public from entering work site.

irrigation maintenance activities

Maintenance 1


Site location : Front lawns outside office

Specific location of irrigation system : see plan below

Problem : One of the Hunter fittings on the semi-automatic pressure system was not attached properly. Required re-fitting and a flush of that part of the system.

Tools Used : Shovel, wheelbarrow, bucket, plumber's tape.

OH&S issues : slippery paving surfaces, a small hole where the hunter fitting had previously been dug out, weather not ideal for maintenance (raining). Surrounding ground already quite wet from rain over night, limiting time able to spend on running the system (don't want to oversaturate site)

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Hunter fitting removed and screen filter removed and washed in soapy water.

New thread tape placed around fitting, opposite to direction it screws in to riser.

Lower sprinkler heads dug up and positioned above soil ready to flush system (heads are on articulated risers). Following flushing, heads replaced with the top kept level to turf. System activated by manual over-ride at solenoid and head alignment adjusted.

Maintenance 2

Site location : propagation house

Type of irrigation system : misting system, using micro-sprinklers.

Work : Remove fittings, clean filters and flush system. Leaf sensor checked and arm balance adjusted appropriately.

Equipment used : bucket, warm soapy water, plumber's tape.

Paving Job at Arthur Circus

Over two days I helped pave a council path at Arthur Circus in Battery Point. This was paid casual work for Botanic Resources.

The existing sandstone pavers were deemed a safety issue for pedestrians given that they were old, cracked, uneven and slippery when wet. These existing pavers were broken up into smaller pieces with a jackhammer and were collected as landfill for another of Botanic Resource's clients. Some of the larger pieces were set aside for other landscaping jobs.

Once all the rubble was collected, the path was excavated to a depth to accomodate the layers needed under the paving (FCR and coarse sand) and to allow the pavers to be slightly above ground level at all points to prevent water pooling on them. Drainage needs to be adequate and usually it is recommended to have a slope or fall away from structures of about 1cm per metre. Stakes with string lines can be useful to ensure there is the correct fall.

The base is laid with FCR and then compacted with a plate compactor.

Prior to operating, it is important to check fuel tank is full, engine oil is at correct level, that there are no loose nuts, bolts or screws, ensure that there are no foreign objects buried shallow in the FCR. Whilst operating this piece of machinery it is important to use protective eye wear and ear muffs, steel cap boots, gloves and full sleeve shirt and long pants. Use two hands to operate compactor and ensure hands, feet and loose clothing are kept clear from moving parts of compactor. Ensure the work area is clear of any obstacles.

It is essential that the base is well-compacted and so the process is repeated until the correct depth is achieved (take measurements from string lines to base). Laying the FCR base outside the boundaries of the project will make it more stable.

Next, a layer of sand is put down. The sand is the glue that holds the pavers in place. The sand is screed smooth to a uniform depth.

Conduit laid down can help to work to desired level and help to screed sand in small sections.

The pipes can be removed, filled in with sand and leveled with a hand held tamper.

The pavers are ready to lay. These pavers were quite heavy and it was important to lift them by bending knees and not taking any strain into back. Each new paver was held at an angle against the edge of a laid paver and gently allowed to slide into place.

Pavers are cut to fit the edges.

The plate compactor may be used again to tamp the paver into the sand. More coarse sand or slightly finer sand can be swept into the joints to lock the pavers. For added durability and lower maintenance, a sealing product can be used, which will keep the sand between the joints in place and help prevent weed growth. A concrete toe is used to hold the two edges of the path together as a restraint.

During the excavation process, one of the lines of the subsurface irrigation system was punctured. A hole was dug to expose the damaged polyethylene (poly) pipe. Items needed for a basic repair are new fittings and/or heads, clamps, a pipe cutter (in this case a hand saw), pliers. Insert fittings tend to make a better connection and in some cases they are the only option for the site because of all the different sizes of poly pipe and configurations that they are available in.

Clear space around all sides of the damaged poly pipe and ensure no rocks or dirt enter the lines. The new fitting is held up to the damaged pipe to measure how much pipe needs to be removed. When bending the pipe to attach the fittings, be careful not to kink the pipe by bending it too much which will significantly reduce its integrity.

Work Placement 1 - TAFE

Area worked in :  Car Park Side Border and Main Border

Activity Tasks : 

March 11th : In a small group we removed all Poa labillardierii and  Lomandra longifolia from the bed. We used mattocks to form a circumferential trench around the grass and then levered the grasses out of the ground. We set these aside for division, propagation and planting elsewhere. We then started weeding out the rope twitch, which is extensive in this bed due to its rhizomatous growth habit and the lack of any form of cultivation in this bed for some time. We discovered localised areas within this bed of very poor drainage and water logging. The soil dug up in these areas had a nasty smell indicating quite poor anaerobic conditions. In addition, all the native pelargonium was pulled out using a pitchfork. We had not previously located and isolated the irrigation system in this bed and I caused a puncture in the poly pipe which required repair the following day. 

March 12th : With assistance from Roy Baker, we repaired the puncture in the irrigation system. This was done by first digging a trench with a shovel and exposing the site. We cut the section of pipe with a hand saw and later Roy obtained replacement piping which we cut to size, filing the edges and attaching to the two ends with plastic couplings. This was a cheap and reasonably quick process. We then flushed the entire section of the irrigation system to remove internal debris and cleaned the filters on each sprinkler. 

March 17th : We continued the process of manually weeding out the rope twitch present with a pitch fork and exposing the irrigation system fully to prevent further damage to it. We then carried out some pH testing using battery operated metres. These metres were calibrated first with known neutral (pH 7.0) solution. A 20g sample of soil was then mixed thoroughly for

 about a minute with 100mL of distilled water, making sure no organic matter contaminated the soil sample.  The meter was placed in the solution, being careful to avoid placing the meter in the soil sediment. To measure the pH we tested a couple of different sites in the bed instead of doing a composite analysis (soil samples taken from many different points in the one site and mixed together). This was because the soil profile at various sites demonstrated it was not 

an homogenous area.  Results are seen in the photo below. 

In the main border there were mixed pH readings of 6.3 and 7.4 where the westringias and hakea had been growing respectively. In the carpark border, pH 6.6 in the clay loam and 6.3 in the sandy loam. In the car park side border, pH 7.3 where a sad acid-loving camelia was growing and 6.4 on the other end. 

Soil texture analysis in this bed showed areas of sandy loam to clay loam.  

March 18th and 19th :  Worked on the main border where turf had been removed for a new section of this border. This area had a hard clay based soil which required breaking up first with a square mouth shovel. Shallow root masses were removed with a garden fork and then a pick-ended mattock was used to break up the clay even further. This was quite a physical exercise and proved more efficient when we worked in sequence, one person following on from the other person in a given area. We then leveled the bed as best we could with a metal rake, using the bottom end to level and the toothed end to break up clods and rake up surface debris. The last job was to place compost which had been previously calculated by the cubic metre in piles one metre apart and then spread by metal rake over the bed to a thickness of about 100mm. 

OH&S issues :  Constant issues included presence of cars and general public accessing area. These were addressed by wearing high visibility vests, placing signs and fluorescent witches hats around the area. There were no underground electrical issues in this bed. Holes left behind following the removal of the grasses became an issue and had to be addressed by leveling these holes. Risks of exposure to sun, potential allergens and insects was managed by wearing the appropriate P.P.E. Unused tools were placed in a corner leaning on a wall cl

ose to but away from the work site to prevent injury. Risk assessment sheets were completed for each day. Examples in photos below : 

P.P.E. : full sleeve shirt, broad brimmed hat, glasses, steel cap boots, long trousers, fluorescent vests. 

Environmental Work Practises : Proper disposal of the rope twitch had to be thought about to limit its spread. We used separate bins for the rope twitch and transported this to a separate section of the compost area. Solarisation by exposure to full sun is a safe and environmentally sound method of disposal of rope twitch. We ensured that we cleaned all equipment that we used prior to returning them to prevent spread of the weed. 

Reflection : It's important to know the location and isolate any underground piping or cables in an area being cultivated. We could have asked for the plans for the irrigation system before we started digging up the area. We could consider using the herbicide fusilade (targets monocotyledons non-specifically) but this would make it difficult to grow other grasses in the bed. Working efficiently means knowing how to use a hand tool effectively, with the least amount of physical exertion and working in a co-ordinated fashion.