Riversdal Piggery, Riversdal - Cape EAPrac Riversdale Piggery/DBAR/G… · The dairy produces 100m3 of wastewater per day and the piggery will produce 250m3 wastewater per day. The

Eco-Owl – Water and Wastewater Solutions A division of: ReSalt Agricultural Systems and Strategies (Pty) Ltd 2007/010733/07

Michiel Meets – [email protected], 082 553 5431

Riversdal Piggery, Riversdal

WASTEWATER SITUATIONAL REPORT IN TERMS OF THE NATIONAL WATER ACT, 1998 (ACT 36 OF 1998), SECTION 21(E):

Engaging in a controlled activity: irrigation of any land with waste or water containing waste generated through any industrial activity or

by a waterworks.

Developed by ECO-OWL, A DIVISION OF RESALT

This material was specifically developed for Endwell farm, Riversdal and may not be duplicated or distributed in any way without written permission from Eco-Owl.

November 2016

©

WASTEWATER SITUATIONAL ANALYSIS

Wastewater Situational Report Riversdal Piggery

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Contents

1. Executive Summary ......................................................................................................................... 3

2. Introduction ...................................................................................................................................... 5

3. Existing Authorizations ..................................................................................................................... 5

4. Wastewater To Be Generated .......................................................................................................... 6

4.1 Background .............................................................................................................................. 6

4.2 Wastewater Volumes To Be Generated .................................................................................... 7

4.3 Wastewater quality analysis ...................................................................................................... 8

5. Soils ............................................................................................................................................... 10

5.1 Soil analyses .......................................................................................................................... 13

5.2 Nutrients added by Wastewater and Extracted by Pastures (kikuyu) ....................................... 16

6. End Use Management Proposed .................................................................................................... 17

7. Summary ....................................................................................................................................... 17

8. Appendixes .................................................................................................................................... 18

Appendix 1 ........................................................................................................................................ 19

Appendix 2 ........................................................................................................................................ 21

Appendix 3 ........................................................................................................................................ 27


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1. EXECUTIVE SUMMARY

Riversdal Piggery is in the process of developing a new piggery on the farm Zoetmelksrivier, 6km North of

Riversdal, which already have an operational dairy. There is currently no wastewater system in place and

the piggery is not operational yet. Therefore, the wastewater quality from other piggeries and dairies that

use the same systems have been studied; using those piggeries and dairies as reference for wastewater

analyses in our calculations.

The dairy produces 100m3 of wastewater per day and the piggery will produce 250m3 wastewater per day.

The slurry will flow into a settling pit to accommodate the daily volume of 350 m3 before it overflows into an

anaerobic dam. At the proposed 175ha pastures to be irrigated, the wastewater treatment system need to

have a total capacity of 41 000m3. This is to ensure adequate storage capacity for the wastewater in the

winter months when irrigation requirements are lower. The amount of waste water produced per month will

be just more than 10 000m3, giving the dam system a holding capacity of just under 4 months.

The irrigation management on the farm will dilute the wastewater with 90% fresh water. This practice is

recommended to ensure quality of the wastewater is in spec with legislative standards. Using kikuyu as a

reference crop, to utilize all the wastewater generated (mixed with fresh water), a total of 175ha need to be

irrigated. This is readily available on the farm Zoetmelksrivier.

The soil profiles have shown the following possible limitations

Table 1 Summary of Soil properties

Sample point

Soil Form Physical restriction

Comments Chemical restriction Suitable for

wastewater management

Impenetrable subsoil horizon

Depth mm

In Subsoil Comments

1

Glenrosa Lithocutanic 900

Crop root depth is

300mm and with

proper irrigation

management

water penetration

can be limited to

root depth. This

will decrease the

risk caused by the

restrictions. A

deep rip could

also help reduce

the risk.

High Na Na is high, input from wastewater is less than crop requirements (see Table 5.10). Where K is high, it is also lower than crop requirements. High Na in the subsoil should not pose a risk due to crop rootzone being 300mm. A gypsum application is recommended (see Table 5.9).

With proper irrigation management, all these soils (areas) are suitable as part of a wastewater management program.

2 High K

and Na

3 Glenrosa/Swartland Pedocutanic 400 High Na

4 Glenrosa Lithocutanic 300 High Na

5 Swartland Pedocutanic 400 None

6 Glenrosa Lithocutanic 600 None

7 Sepany Pedocutanic 600 High Na


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No insurmountable limitations have been identified and with proper management, all possible restrictions

can be overcome and all the soils (areas) sampled can be used as part of a wastewater management

program.

The wastewater treatment must include pH adjustment to correct the pH when needed. The EC in the

wastewater is also excessive. To ensure quality of the irrigation water remains adequate, systems for COD

removal (such as active aeration) and the removal of suspended solids need to be investigated. An

anaerobic/ aerobic treatment system in the containment lagoons are recommended.

To confirm above mentioned quality parameters, the quality of the dairy and piggery wastewater

must be monitored as soon as the whole system is operational.

Wastewater samples need to be taken every month and analysed to enable adjustments to management

practices if required. Soil samples need to be taken annually to confirm the efficiency of the management

system. Wastewater volumes need to be calculated preferably on a daily basis. This in conjunction with the

monthly wastewater analysis, must be used to adjust the irrigation management.

A management plan is a working document and need to be adjusted continually to confirm or amend the

existing system.


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2. INTRODUCTION

Riversdal Piggery is in the process of developing a new piggery on the farm Zoetmelksrivier 6km North of

Riversdal. For authorisation purposes, they are proposing irrigation as the method of disposal of the

wastewater that will be generated on the farm. The wastewater will include both wastewater from a dairy

and a piggery.

Eco-Owl (a division of ReSalt), have determined the storage capacity and irrigation areas needed for the

disposal of Riversdale Piggery’s wastewater, and have identified a management option using irrigation.

There is currently no wastewater system in place and the piggery is not operational yet. Therefore, the

wastewater quality from other piggeries and dairies that use the same systems have been studied; using

those piggeries and dairies as reference for wastewater analyses in our calculations. The following report

contains information regarding the storage capacity required for wastewater, areas for irrigation sites planted

to kikuyu or other pastures, summary of wastewater quality analyses as well as treatment options that may

be investigated.

3. EXISTING AUTHORIZATIONS

New piggery and dairy wastewater management system to be established. No existing authorizations


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4. WASTEWATER TO BE GENERATED

4.1 BACKGROUND

Riversdal Piggery will be constructed on the same farm as an existing dairy. The dairy supplies milk to a

cheese factory in the town of Riversdal. The whey from the cheese factory will be used as part of the feed

ration for the piggery. The wastewater generated by the piggery and the dairy will then be irrigated onto

pastures on the same farm. This piggery will be a replica of another piggery in Bonnievale. Data from the

Bonnievale piggery were used in the calculations for the wastewater treatment and utilisation. Due to a wet

feed system being used for the piggery, the total solids in the waste stream will be very low. The maximum

total solids will be 9%. For these calculations (and as measured in Bonnievale) a 6.5% total solids value

were used for the piggery waste. Each pig should produce approximately 11ℓ of slurry a day. The value of

total solids of the dairy waste stream is 8%.

Waste management process:

There will be a total of 22 500 pigs on the farm at any one time. All the urine and manure from the pens will

fall through slats in the floor into a pit. This pit is then flushed weekly by pulling a plug and it gravitates to a

collection sump. The wastewater from the dairy will also flow into this collection sump. Here the solids are

screened using a press auger where approximately 6% of the total volume (at a total volume of 350m3 /d,

with 7% total solids (24.5 m3/d). The solids will be spread on a concrete floor and collected weekly to be

composted.

The rest of the slurry will flow into a settling pit to accommodate the daily volume of 350 m3 before it

overflows into an anaerobic dam. The settling pit will be cleaned once a year (when it has reached 75% of

capacity). The anaerobic lagoon will have a capacity of 14 000m3, which gives a retention time of 40 days

(given slurry volume of 350m3/day). From this lagoon, the water overflows to an aerobic lagoon (with the

same capacity) where the water will be aerated. Due to variation in irrigation needs between the winter and

summer, the water from the aerobic lagoon should be sent to a holding dam from where it is irrigated unto

pastures. The total volume of the lagoon treatment system will be 35 000m3.

Current wastewater flow

Currently the wastewater generated by the dairy is approximately 100m3 per day, and this wastewater flows

into a lagoon. This wastewater will be managed by the same new system that will be constructed for the

piggery. The piggery has not been constructed yet, and the following report is therefore based on an

estimated wastewater volume and quality that will be generated on the farm.

Wastewater from the dairy will also be directed through the same wastewater system.


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4.2 WASTEWATER VOLUMES TO BE GENERATED

Riversdal Piggery provided us the estimated wastewater volumes using data from their other farms. These

estimated wastewater volumes were used in calculations in this report (refer to Table 3.1 – Table 3.5). The

wastewater volume from the dairy is currently 100m3 a day and the piggery will produce a volume of 250m3

per day. The total wastewater volume of the farm will be 350m3 per day. Very little variation in seasonality is

foreseen, but can only be confirmed once the piggery is in full operation.

Irrigation of pastures using kikuyu as a reference crop:

The farm has a total area of 200 ha readily available for irrigation and can be utilised as pastures by the dairy

cows. To ensure that the wastewater quality meets the DWS norms it is recommended to mix the wastewater

with 90% fresh water. This is also the proposed method of irrigation by the farmer. Comparing the water use

of kikuyu grass and the total amount of wastewater that will be generated (and the fresh water that will be

needed is considered), at least 175ha must be irrigated to consume the total volume of wastewater.

Table 4.1 Monthly water balance for pastures and the total volume of wastewater utilised

Period Evaporation1

Effective rainfall1

Crop factor

(pastures)

IR2 (pastures)

Waste water3

Waste water

Wastewater needed when mixed 90% with fresh water

Volume fresh water at 90%

fresh water on 1ha (m3)

Volume wastewater needed on 1ha (m3)

(mm) (mm) (mm) (mm) (m3) 100 ha 175 ha

January 163 24 0,85 154 1 085 10 850 15 371 26 898 1 383 154

February 132 35 0,85 107 980 9 800 8 592 15 037 988 86

March 119 34 0,85 94 1 085 10 850 7 487 13 103 861 75

April 88 57 0,8 32 1 050 10 500 2 546 4 455 293 25

May 68 35 0,7 30 1 085 10 850 2 395 4 191 275 24

June 57 38 0,6 15 1 050 10 500 1 204 2 108 138 12

July 60 36 0,6 19 1 085 10 850 1 485 2 599 171 15

August 72 45 0,6 21 1 085 10 850 1 697 2 970 195 17

September 92 34 0,7 53 1 050 10 500 4 208 7 364 484 42

October 120 48 0,8 75 1 085 10 850 5 990 10 483 689 60

November 141 33 0,85 119 1 050 10 500 9 547 16 708 1 098 95

December 167 34 0,85 146 1 085 10 850 11 713 20 498 1 347 117

Totals 1278 453 127 750 72 237 126 414 1Weather data obtained from the Cape Farm Mapper (http://gis.elsenburg.com/apps/cfm/#) and DIVA-GIS (www.diva-gis.org) 2 Irrigation requirements = evaporation x crop factor x system efficiency (70%). 3 Generated wastewater, expressed as mm irrigation water over 1.0 ha.


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Table 4.2 Size of the storage dam and the period of storage vs. the irrigation area (kikuyu)

Total surface area of pastures (ha)

Period that the wastewater must be

stored (months)

Size of the required containment dam

(m3)1

100 10 61 000

150 7 45 611

175 7 40 730

200 6 36 979

250 5 30 000 1 As the area decreases the period of storage and the size of the required containment dam will increase accordingly.

4.3 WASTEWATER QUALITY ANALYSIS

Tables 4.3 gives a summary of the wastewater analyses of a similar piggery and dairy. At the representative

piggery, there has been solid separation, a settling pit, two anaerobic dams for water treatment and an

overflow dam from where water is taken for irrigation. The tables shows an increase in water quality from

the raw effluent to the final irrigated water, highlighting the importance of a waste water treatment system.

For a more detailed analysis of the different samples taken at the representative piggery see Appendix 1.

Table 4.3 Comparison of averages at different treatment stages for a representative piggery

Parameter Unit Limits3 Raw

Wastewater

Retention pond outlet

Anaerobic pond

Dairy Final

Irrigation2

pH - 6 - 9 8,4 7,19 7,6

EC mSm <200 1412 140 2131

COD mg/l <400 32 700 2 708 5 8951 171 309

Suspended solids mg/l <25 6 698 243 7031 124 105

SAR - <5 4,4 3,9 1,62 3.5

Na mg/l 278 158 81,9 90.8

K mg/l 1 017 735 166

Ca mg/l 188 82 77,6 40

Mg mg/l 86 16 52,1 28

NH4 mg/l 818 1 028 45 32

PO4 mg/l 451 66 33 15

SO4 mg/l 419 49 44,8

Cl mg/l 2 321 1 014 326,5 1Highlighted values in Table 4.3 is out of the range of parameters (refer to Limits) as stipulated for the irrigation of between 50m3 and

500m3 per day onto kikuyu or pastures. This will need to be confirmed once the piggery produces its own wastewater. 2 The final irrigation will be a 10% of a mix of dairy wastewater (29%) and piggery wastewater (71%) and 90% fresh water. 3 Wastewater parameters for kikuyu irrigation for 50 – 500m3 per day as determined by DWS.

When comparing the anticipated wastewater quality (as analyzed for Bonnievale piggery and the dairy on

the farm) and the parameters as set out for the beneficial irrigation of kikuyu and pastures, the following

were identified:


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According to available analyses the pH of the wastewater before treatment (at the retention pond) complies

to the norm of 6 – 9. Only the final irrigation water complies to the chemical oxygen demand (COD) norm of

<400mg/l, keeping in mind that this was mixed 90% with fresh water. The sodium adsorption ratio (SAR) is

below the maximum of 5 for all the wastewaters analysed. The electrical conductivity (EC) is higher than

the legal requirement for kikuyu/ pasture irrigation (EC < 200 mS/m), even at the irrigation water stage. This

however is just above the limit and with proper control and management, the legal norm can be achieved.

Water analysis must be taken monthly to ensure proper management of the waste water. The samples

should be taken at the point of inflow into the dam from the dairy and the piggery respectively. Samples

must also be taken in all the dams and a sample of the irrigated water. For instructions in taking water

samples, please refer to Appendix 3.

Please note that these analyses are only indicative and once the operation is fully running, new water

samples should be taken to compare and adjust the system where needed.


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5. SOILS

A soil study of the farm was conducted in 2006 by Dr. Piet le Roux et al. (see Appendix 2 for the report).

From this soil study a map was developed shown in Figure 5.1.

Soil samples 1, 2, 4 and 6 were taken in Glenrosa soil. In area 1 and 2 the A horizon is 200 – 300mm deep.

The lithocutanic B horizon has high weathering and has approx. 75% rock. The effective root depth in these

soils are 900 – 1400 mm and the SWHC is higher that soil areas 4 and 6.

In area 4 the soil is very shallow and has an orthic A horizon (200 – 300mm) on a lithocutanic B horizon

which is approximately 95% rock. The soil has a low water holding capacity.

In area 6 the soil depth is approximately 900mm and the B-horizon has a larger amount of weathering than

the shallow soil above with approx. 80% rock. These soils have a better soil water holding capacity (SWHC)

than the above-mentioned soil.

Area 3 represents a Glenrosa/ Swartland soil. The soil is on the transition of the above Glenrosa and the

Swartland below. The effective soil depth is characteristic of the Swarland below, but with regards to lime

and a rocky B-horizon is reminiscent of the Glenrosa above.

Area 5 has Swartland characteristics, where the soil has an orthic A horizon between 250mm and 300mm

and pedocutanic B horizon between 400mm and 600mm. There are signs of water logging.

Area 7 is represented by a Sepany soil. It has a orthic A horizon approximately 250 – 300mm deep with

15% clay. The pedocutanic B horizon is 400mm – 600mm with a clay of 25 – 30%. It lies on unspecified

material with signs of water logging.

Table 5.1 Summary of Soil properties

Sample point

Soil Form Physical restriction

Comments Chemical restriction Suitable for

wastewater management

Impenetrable subsoil horizon

Depth mm

In Subsoil Comments

1

Glenrosa Lithocutanic 900

Crop root depth is

300mm and with

proper irrigation

management

water penetration

can be limited to

root depth. This

will decrease the

risk caused by the

restrictions. A

deep rip could

also help reduce

the risk.

High Na Na is high, input from wastewater is less than crop requirements (see Table 5.10). Where K is high, it is also lower than crop requirements. High Na in the subsoil should not pose a risk due to crop rootzone being 300mm. A gypsum application is recommended (see Table 5.9).

With proper irrigation management, all these soils (areas) are suitable as part of a wastewater management program.

2 High K

and Na

3 Glenrosa/Swartland Pedocutanic 400 High Na

4 Glenrosa Lithocutanic 300 High Na

5 Swartland Pedocutanic 400 None

6 Glenrosa Lithocutanic 600 None

7 Sepany Pedocutanic 600 High Na


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The wastewater irrigated area(s) may not be situated in a water course and must be located above the

1:100 year flood line or riparian habitat, whichever is the greatest, or alternatively, at least 100 meters from

a natural water resource (e.g. river, storm water furrow, etc.) whichever is the greatest; or at least further

than a 500 meter radius from a borehole that is utilized for drinking water or stock watering; and at least

outside a 500 meter radius from the boundary of a wetland; and that the disposal site may not overlie a

major aquifer.


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Figure 5.1 Map showing the different soil types and points where soil samples were taken


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5.1 SOIL ANALYSES

The soils have been sampled for chemical analyses at depths 0 - 30cm and 30 - 60cm and 60 - 90cm

(where possible). Bemlab conducted the chemical analyses summarised in Tables 5.3 to 5.9.

Table 5.2 show the GPS coordinates of the soil sampling points for reference when annual samples are to

be taken for auditing purposes. See Appendix 3 for soil sampling methods.

Table 5.2 Position of the soil samples taken (WGS 84 format)

Description Latitude/Longitude Altitude (HASL)

Soil 1 (RIV 1) 34° 08'23.04"S & 21°17'18.49"E 154m

Soil 2 (RIV 2) 34° 08'15.57"S & 21°17'05.55"E 144m

Soil 3 (RIV 3) 34° 08'06.50"S & 21°17'14.30"E 161m

Soil 4 (RIV 4) 34° 07'54.21"S & 21°17'15.34"E 136m

Soil 5 (RIV 5) 34° 08'13.52"S & 21°17'28.21"E 165m

Soil 6 (RIV 6) 34° 08'04.36"S & 21°17'42.66"E 154m

Soil 7 (RIV 7) 34° 08'16.73"S & 21°16'37.91"E 91m

Table 5.3 Soil 1 (RIV 1)

Depth Soil Texture

pH Stone Resistance P Bray II K Na K Ca Mg C

(cm) (KCl) (Vol %) (ohm) (mg/kg) (mg/kg) (cmol(+)/kg) (%)

0 - 30 Clay 6,4 18 570 24,56 132,36 0,55 0,34 3,71 2,74 1,19

30 -60 Clay 5,3 50,1 250 2,15 225,95 1,53 0,58 4,62 6,08 0,65

Base Saturation and Water holding capacity (WHC)

Depth Na K Ca Mg WHC mm/m (cm) (%)

0 - 30 7,46 4,61 50,57 37,36 95,7

30 -60 11,31 4,26 34,07 44,83


Depth Soil Texture



0 - 30 Clay 6,9 47,9 410 15,55 235,07 0,95 0,60 15,64 3,49 1,48

30 - 60 Clay 7,9 31,7 530 0,08 44,50 1,24 0,11 21,22 3,74 0,62

60 - 90 Clay 7,9 36,8 500 0,18 53,10 1,47 0,14 20,19 4,55 0,41



0 - 30 4,60 2,91 75,62 16,88 58,04

30 - 60 4,73 0,43 80,64 14,21

60 - 90 5,57 0,52 76,65 17,27


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Depth Soil Texture



0 - 30 Clay 6,8 31,8 470 18,61 49,55 0,67 0,13 7,87 2,44 1,27

30 - 60 Clay 6,5 49,9 400 28,62 36,03 0,88 0,09 5,06 2,25 1,01

60 - 90 Clay 6,7 47,4 240 0,98 36,70 1,82 0,09 2,03 3,33 0,37



0 - 30 6,08 1,14 70,85 21,93 92,73

30 - 60 10,59 1,11 61,16 27,14

60 - 90 25,02 1,29 27,94 45,75


Depth Soil Texture



0 - 30 Loam 5,7 34,6 970 59,69 63,44 0,35 0,16 3,13 2,23 1,27

30 - 60 Clay 5,4 68,3 590 4,05 38,76 1,08 0,10 3,93 4,64 0,90



0 - 30 5,54 2,54 49,01 34,94 91,3

30 -60 10,39 0,95 37,82 44,66


Depth Soil Texture



0 - 30 Clay 7,2 0,9 810 51,16 119,68 0,27 0,31 15,88 2,11 1,22

30 - 60 Clay 7,6 33,7 730 0,95 61,12 0,89 0,16 22,76 2,55 0,92

60 - 90 Loam 7,8 32,8 550 0,56 64,84 1,00 0,17 20,84 2,64 0,49



0 - 30 1,46 1,65 85,53 11,36 125,09

30 - 60 3,39 0,59 86,36 9,66

60 - 90 4,04 0,67 84,57 10,71


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Depth Soil Texture



0 - 30 Clay 7,6 34,2 680 39,82 106,94 0,28 0,27 22,39 2,21 1,07

30 - 60 Clay 7,7 44,3 680 1,46 91,95 0,44 0,24 22,44 3,27 0,84



0 - 30 1,13 1,09 89 8,79 83,83

30 -60 1,67 0,89 85,05 12,38


Depth Soil Texture



0 - 30 Clay 7,0 0,9 610 34,48 45,78 0,50 0,12 4,73 1,70 0,82

30 - 60 Clay 6,5 9,8 220 1,24 115,03 2,13 0,29 6,58 4,98 0,53

60 - 90 Clay 6,8 39,1 280 0,58 130,98 1,22 0,33 3,93 4,58 0,19



0 - 30 7,14 1,66 67,03 24,17 130,63

30 - 60 15,20 2,10 47,07 35,62

60 - 90 12,08 3,33 39,03 45,55

Soils 1, 2, 3, 4, and 7 have very high Mg (Magnesium) and Na (sodium) concentrations. This can be due to

the areas affected being under irrigation and the elements dissolving from the shale underneath. This may

also be the reason why the sodium in the subsoil is higher in most cases. However, this could pose a risk

when irrigating with waste water that contains these elements. It is therefore strongly recommended, as was

pointed out in the soil report done in 2006, to rip the soil to at least a depth of 600 – 750mm. It is also

recommended to apply gypsum to the soil at various rates and then do an annual maintenance addition of

gypsum of 1 ton /ha. The recommendations for gypsum to be added can be found in Table 5.10.

Table 5.10 Gypsum addition

Sample Amount of gypsum (ton/ha)

2017 2018 2019 +

RIV 1 5 1 1

RIV 2 5 5 1

RIV 3 5 4 1

RIV 4 3 1,2 1

RIV 5 4 1,5 1

RIV 6 1 1 1

RIV 7 5 5,09 1


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5.2 NUTRIENTS ADDED BY WASTEWATER AND EXTRACTED BY PASTURES (KIKUYU)

Table 5.11 shows the nutrient requirements that will be needed to produce a yield of 10t/ha dry material

from the kikuyu pastures. These nutrients will partially be supplied by the wastewater (as analysed) as

indicated (for 100ha and 175ha). It is assumed that 175ha will be irrigated to manage the total amount of

wastewater and the amount of extra plant nutrients needed are also shown in the Table 5.11.

When applying the nutrients through wastewater it is inevitable that some nutrients will be supplied in

excess. These nutrients will be Ca (calcium), Mg (magnesium) and S (sulphur). The red highlight indicates

the surplus amounts of nutrients applied (in kg). Addition of gypsum will ensure the Ca:Mg ratio will stay

within range. The amount of S that will be added by the gypsum applications should not pose any problems.

Sodium (Na) in the wastewater (see table 3.3f) can be high and, added to soils that already have high levels

of sodium, could pose risks. However, the crop will take-up more Na than is delivered if the K concentrations

are adequate. This need to be managed by addition of gypsum and could also be enhanced by selection of

certain plant types for pastures. A crop rotation system needs to be investigated further, but is outside the

scope of this study.

Table 5.11 Nutrients removed by pastures (kikuyu) and nutrients added by the waste water

Nutrient

Kikuyu nutrient removal Hectares (ha) Amount of Nutrients (kg/ha)

1 ha (@ 10 ton/ha yield) 100 175 175 Nutrient needed/excess1 Removed Removed Removed Added with WW

K 320 32 000 56 000 20 985 11 015

Ca 16,25 1 625 2 844 5 104 3 479

Mg 7 700 1 225 3 553 2 853

N 340 34 000 59 500 4 022 29 978

P 41 4 100 7 175 599 3 501

S 7 700 1 225 1 888 1 188

Na 85 8 500 14 875 11 476 13 024 1 The last column indicates if extra nutrients are needed besides the wastewater or if a nutrient is applied in excess through the wastewater.


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6. END USE MANAGEMENT PROPOSED

According to calculations based on the information gathered, there will be enough wastewater to irrigate at

least 150 ha of pastures. Due to the capital implications for storing water in the wet months, it is

recommended to irrigate at least 175ha with diluted (90:10) wastewater (9:1). This will ensure utilisation of

most of the wastewater through the year, keeping in mind that the wastewater will be mixed with 90% fresh

water. At 175ha a containment dam of 41 000m3 will be needed. If the system is divided in three where two

dams are used to treat the water and the last as an holding dam, each dam must be approximately

14 000m3. The amount of waste water produced per month will be just over 10 000m3, giving the dam

system a holding capacity of just under 4 months. That gives a water treatment system with an anaerobic/

aerobic (depending on the system chosen) retention time of 40 days in each of the two treatment dams.

Wastewater volumes need to be calculated preferably daily and with the monthly wastewater analysis it

must be used to adjust the irrigation management. Wastewater samples need to be taken every month and

analysed to adjust management options if needed and soil samples need to be taken annually to confirm

management system. See Appendix 3 for water sampling methods.

7. SUMMARY

Information needed to propose irrigation as the end-use of the dairy and piggery wastewater was provided.

Using data from similar facilities it is concluded that the quality of the wastewater must be improved if the

end use is irrigation. The wastewater treatment must include pH adjustment to correct the pH when needed.

The EC in the wastewater is also too high. If no fresh water is available for dilution, better methods for COD

removal (such as active aeration) and suspended solids need to be investigated. An anaerobic/ aerobic

treatment system in the containment lagoons are recommended. To confirm above mentioned quality

parameters, the quality of the dairy and piggery wastewater must be monitored and adjusted as necessary.

A management plan is a working document and need to be adjusted continually to confirm or amend the

existing system.


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8. APPENDIXES


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APPENDIX 1

Detailed wastewater analyses from a similar piggery in Bonnievale

This data was used in the calculations in the report as mentioned earlier.

Table A Analysis of raw wastewater

Units Limits Average Min Max

COD mg/l 400 32700 4650 55980

Suspended solids mg/l 25 6698 258 25200

SAR - 5 4,4 0,0 10,2

Na mg/l 278 122 541

K mg/l 1017 517 1772

Ca mg/l 188 126 283

Mg mg/l 86 25 158

NH4 mg/l 818 9 1354

PO4 mg/l 451 224 724

SO4 mg/l 419 68 1226

Cl mg/l 2321 592 6799

Table B Analysis of retention pond wastewater


pH - 6 - 9 8,4 7,4 8,8

EC mSm 200 1412 815 2130

COD mg/l 400 2708 1250 4107


Table C Analysis of anaerobic dam wastewater


COD mg/l 400 5895 3243 9800


SAR - 5 3,9 0,0 9,0

Na mg/l 158 97 255

K mg/l 735 380 1290

Ca mg/l 82 39 169

Mg mg/l 16 5 29

NH4 mg/l 1028 11 2364

PO4 mg/l 66 36 89

SO4 mg/l 49 41 62

Cl mg/l 1014 0 1974


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Table D Analysis of final irrigation water1 (for the piggery used as a model)


pH - 6 - 9 7,9 6,5 8,7

EC mSm 200 253 146,6 425

COD mg/l 400 383 23 700


SAR - 5 4,4 0 7,02

Na mg/l 133 16,2 272,2

K mg/l 166 7,3 371,2

Ca mg/l 22 10,7 37,32

Mg mg/l 18 6,1 32

NH4 mg/l 26 13,3 39,6

PO4 mg/l 7,0 3,2 11,7

SO4 mg/l 44,8 35,61 55,55

Cl mg/l 326,5 247,227 392,9

1 Note that with the final irrigation at this piggery the waste water is mixed with fresh water up to 95%. **Faecal coliforms were not analysed – it must be analysed monthly

Table E Dairy waste water analysis

Units Average

pH 7,19

EC mSm 140

COD mg/l 171

Suspended solids mg/l 124

SAR - 1,62

Na mg/l 81,9

K mg/l

Ca mg/l 77,6

Mg mg/l 52,1

NH4 mg/l 45

PO4 mg/l 33


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APPENDIX 2

Soil study report done in 2006 for the area concerned. The report was written in Afrikaans.

Grondverslag aan Jireh-Boerderye na aanleiding van die grondprofiele wat ondersoek is op 27 en 28 Maart 2006 deur Dr. Piet le Roux, Coenrad Fraenkel en Ian Bothma Glenrosa Vlak Glenrosa’s

Vlak Glenrosas het ‘n ortiese A horison (200 tot 300 mm) op ‘n litokutaniese B horison wat bestaan uit ongeveer 95% klip. Die dominante familie is 2111 Overberg Wortels van die bestaande lusern dring 400 tot 600 mm diep die grond binne. Die waterhoevermoë is dus laag en meerjarige weidingsgewasse word op die gronde aanbeveel. Die effektiewe worteldiepte – en dus waterhouvermoë van die gronde - kan aangehelp word ‘n diep skeurploeg-aksie op die gronde toe te pas wat die skalies in die litokutaniese B horison kan opbreek en die proses van verwering aangehelp word. Meduim Glenrosas


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Die meduim Glenrosas se B horison het ‘n hoër graad van verwering as die vlak Glenrosas - ongeveer 80% klip. Die families wat voorkom is die nie-kalkhoudende (2111) Overberg en die kalkhoudende Inverdoorn (2112). Die effektiewe worteldiepte is ongeveer 600 tot 900 mm. Die gronde beskik dus oor ‘n beter waterhouvermoë as wat die geval is met vlakker Glenrosas. Daar word aanbeveel dat meerjarige weidingsgewasse op die gronde verbou word. Die effektiewe worteldiepte en water stoor vermoë van die gronde kan aangehelp word ‘n diep skeurploeg-aksie. Diep Glenrosas

Diep Glenrosas het ook A horisonte van 200 tot 300 mm. Die litokutaniese B horison is meer verweer en ongeveer 75 % klip. Hierdie Glenrosas is van die Inverdoorn (2112) familie. Die effektiewe worteldiepte van die gronde is 900 tot 1400 mm. Die gronde se waterhouvermoë is in die algmeen aansienlik beter as wat die geval is met die bostaande 2 Glenrosas. Die litokutaniese B horison is baie kalkryk soos gesien kan word op die foto. Die effektiewe worteldiepte en water stoor vermoë van die gronde kan aangehelp word ‘n diep skeurploeg-aksie. Na verbetering kan die grond geskik wees vir die verbouing van eenjarige gewasse.


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Sepane:

Die Sepane grondvorm hett ‘n ortiese A horison van ongeveer 250 tot 300 mm met ongeveer 10-15 % klei. Die pedokutaniese B horison 400 tot 600 mm met ‘n klei inhoud van 25-35 %. Die hoekige blok struktuur gee aanleiding daartoe dat die plantwortels oor die tussen die peds deur beweeg. Dit le op ongespesifiseerde materiaal met tekens van natheid. Die gronde se waterhouvermoë is goed. Die voorkoms van die ongespesifiseerde materiaal met tekens van natheid kan versuip en verbrakkings probleme veroorsaak onder besproeing.

Swartland: Swartland (met tekens van natheid)

Hierdie gronde van die Swartland grondvorm het ‘n apedale ortiese A horison van 250 tot 300 mm (klei-inhoud 15 %) en pedokutaniese B horison van 400 tot 600 mm (klei-inhoud 25-35 %). Die pedokutaniese B horison het ‘n sterk grof hoekige blok struktuur. Die wortels groei tussen die peds deur. Dit word onderle deur ‘n skalie laag en ‘n 50 mm laag met tekens van natheid net bo die skalie. Dit is ‘n aanduiding dat behalwe die gebrek aan diepte daar ‘n verdere gevaar van versuiping is. ‘n Skeurploeg-aksie kan die graad van dreinering aansienlik verbeter en die besproeings vermoë van die grond verhoog. Die Swartland behoort tot die Bonnievalle familie 2221.


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Swartland (op litokutaniese B)

Die lande rondom die melkstal het gronde van die Swartland wat nie tekens van natheid het nie en die pedokutaniese B horison word opgevolg deur ‘n litokutaniese B horison wat die effektiewe diepte van die grond aansienlik verbeter. Die effektiewe worteldiepte en water stoor vermoë van die gronde kan aangehelp word ‘n diep skeurploeg-aksie. Katspruit:

Die Katspruit se horisonopeenvolging is ortiese A horison van ongeveer 250 tot 350 mm wat opgevolg word deur ‘n G horsont wat ‘n aanduiding is dat die grond vir die grootste deel van die jaar met water versadig is. Waar dit oorweeg word om enige gewasse op die gronde aan te plant moet vlak wortel gewasse oorweeg word wat nie baie gevoelig is vir versuipings toestande nie.


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Dundee:

Die Dundee grondvorm se gestratifiseerde alluvuim (gevorm deur rivier afsettings). Dit het verdigtingslae wat in die grond voorkom weens die gelaagdheid wat in die gronde. ‘n Diep skeurploegaksie kan baie voordele inhou deur dat dit die verdigtings lae opbreuk en sodoende die wortel en water indringing van die grond verbeter.

Tukulu:

Die Tukulu grondvorm bestaan uit ‘n apedale ortiese A horison van ongeveer 250 tot 350 mm opgevolg deur ‘n neokutaniese B horison (tot 1000) met ‘n baie gunstige wortelmeduim vir plante asook waterverspreiding binne die grond. Op 1 000 mm kom daar ongespesfiseerde materiaal met tekens van natheid voor wat daarvoor verantwoordelik is dat die grond versuip toestande kan ondergaan as daar oorbesproei word.


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Oakleaf:

Die gronde is soortgelyk aan die Tukulu behalwe dat daar kom geen tekens van natheid onder die horisonte voorkom nie wat dit ‘n baie meer gunstige grond vir besproeing maak as wat die geval is met ‘n Tukulu omdat die kanse vir versouting en vesrsuiping nie bestaan nie.

Invloed van ploeg op horisonte in die profiel.

In bostaande foto is die rooi sooie van die pedokutaniese B horison en die vaalgrys sooie van die ortiese A horison sigbaar. Dit kan ‘n negatiewe effek he wat veroorsaak word deur die pedokutaniese B wat op die oppervlak voorkom en kan aanleiding gee tot dispersie en dus korsvorming op die oppervlak.


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APPENDIX 3

Soil and Water Sampling methodology

Water Sample Collection

Water analyses - Sampling For Microbiological Analysis

Approximately 100ml water per sample Any clean bottle can be used, however it must be sterilised, i.e. boil the container & the lid. Bemlab also supplies sterilized containers as part of our service. Ask at Reception. If sample is taken from a tap or pump, let the water run for about five minutes before taking the

sample. This will ensure that any build-up in the pipes is washed clean and does not form part of the

sample. The bottle must not be filled to the top, leave a small space open so that the sample can be

shaken in the laboratory. Keep the sample cool (under 10 °C), and deliver to us as soon as possible, and do not expose

the bottle to direct sunlight. Ideally the water sample should reach the laboratory within 24 hours. Mark the bottle clearly

Sampling For Chemical Analysis A minimum of one liter water per sample is required.

Bottle to be clean, but not necessary to be sterilised. Bemlab also provides fit-for-purpose bottles as part of our service.

Before taking the sample, wash the bottle and lid out with the water to be tested if the container was not provided by Bemlab.

If sample is taken from a tap or pump, let the water run for about five minutes before taking the sample.

This will ensure that any build-up in the pipes is washed clean and does not form part of the sample.

Bottle to be filled right to the top, so that as little air as possible is in the bottle. Sample to reach us any time, but as fresh as possible. Mark the bottle clearly

Soil Samples

The purpose of soil samples and analysis is:

to classify soils in order to suggest practices for fertilizer and lime application; to predict the probability of a profitable reaction to application of fertilizer; to evaluate soil fertility; to determine which specific soil conditions could be improved by applying soil amendments; and to detect and correct imbalances in nutrient concentrations.

If the soil is very stony and the stones are so large that it can not be sampled, an estimate of the incidence of stones must be made, i.e. indicate the volume occupied by stones. This information must accompany the soil samples to the laboratory as it can have an appreciable effect on the fertiliser recommendation. A


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stone correction is used in the estimation of gypsum, lime, potassium and phosphate fertiliser requirement. The stone correction is estimated as follows:

Stone correction = 1 – (Stone %) / 100) (2.1) Where: Stone % in v/v Volume % stone can be calculated from mass % stone with Equation 2.2 (Avery & Bascomb, 1974) and conversions at selected soil bulk densities are shown in Table 2.1.

Volume % = [(Mass % X b)/((100 – Mass %) X d) + (Mass % X b ))] X (2.2)

Where Mass % is the mass percentage stone in the sample b the bulk density of the soil in g/cm3 d is the density of the stone fraction. It is normally taken as 2,7 g/cm3

Table A1: Volume % equivalents of Mass % estimates of stone content Mass % Stone Volume % Stone at soil bulk density (g/cm3) of

0,5 1,0 1,3 1,5 1,7 2,0

5 1 2 2 3 3 4

10 2 4 5 6 7 8

15 3 6 8 9 10 12

20 4 8 11 12 14 16

25 6 11 14 16 17 20

30 7 14 17 19 21 24

35 9 17 21 23 25 29

40 11 20 24 27 30 33

45 13 23 28 31 34 38

50 16 27 33 36 39 43

55 18 31 37 40 43 48

60 22 36 42 45 49 53

65 26 41 57 51 54 58

70 30 46 53 56 60 63

75 36 53 59 63 65 69

80 43 60 66 69 72 75

85 51 68 73 76 78 81

In vineyards it is desirable to collect samples from the topsoil and subsoil separately. It is also often desirable

to sample underlying clay material separately, since salts can move upwards to the overlying soil layers

during dry periods.

Existing fields

Samples are collected per management unit. The depth of sampling must be indicated. To ensure that the

samples are representative of the unit, it is once again constituted from sub-samples which are taken from

different places in the unit. If the soil has been ridged, the samples should be taken from the ridge only.

Samples must be taken every year. Because soil composition can vary drastically over short distances,

long term trends can best be determined if samples are collected more or less at the same places at

plants that are representative of the field/orchard. Areas should be marked with a GPS coordinate for

this purpose. Weak patches in the field should be sampled separately.


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It is seldom necessary to sample deeper than 600mm. If the soil is shallower than 450-500mm, sampling

should be limited to above the restricting layer. If underlying clay is included in the sample, it can affect the

results to such an extent to render them totally useless. One kilogram (1kg) of soil is sufficient for a sample.

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