INTRODUCTION

Based on Ministry regulation No. 68 of 2016 it is explained that domestic wastewater is waste water produced from various forms of household activities (Pangestu, 2021). Some of the waste comes from latrines and some comes from bathrooms, washing clothes, kitchen utensils and eating and drinking utensils that contain leftovers. Waste requires processing if it turns out to contain polluting compounds that result in creating damage to the environment or potentially creating pollution (Ginting, 2007). Meanwhile, sewage sludge if not treated properly can produce contaminants that have the potential to pollute water bodies because they do not meet water quality standards (Kristanto, 2004). Waste quality shows the specifications of the waste as measured by the amount of pollutant content in the waste which consists of various parameters (Muthawali, 2013). The smaller the parameter and the concentration, the smaller the chance for environmental pollution (Lukman, Pratiwi, & Rosdiana, 2021).

The Nipa-Nipa IPLT was built in 1999, renovated in 2013 by building an Imhoff tank and a sludge drying building as well as sanitation facilities such as water for rinsing and so on. This WWTP is capable of treating 100 m³/day of sewage based on the initial design. The treatment unit at this IPLT consists of an Imhoff tank, a Solid Separation Chamber (SSC) pond, an anaerobic pond, a Sludge Drying Bed (SDB), a facultative pond, and a maturation pond. Sludge treatment at the IPLT is an advanced treatment, because the sewage sludge that has been treated in the septic tank is not suitable for disposal to the environmental media. Sludge that accumulates in the pits and septic tanks that are regularly drained or emptied is then transported to the IPLT using a fecal truck. It's just that in Makassar City itself, the use of septic tanks in accordance with SNI is still very minimal and this also affects the performance of the IPLT. Moreover, Sanitation management practices were discovered to not be applied systematically to drive strategic, long-term sanitation service (Chong, Abeysuriya, Hidayat, Sulistio, & Willetts, 2016).

Based on the existing conditions of the Makassar City Nipa-Nipa IPLT and paying attention to the management system carried out, it is feasible to conduct research in terms of several aspects, namely technical aspects, institutional aspects and financial aspects. This is considering that Makassar City with an area of 175.77 km² and a population of 1,423,877 people is a large city with a population density of 15 sub-districts that are quite diverse, where the highest population density is located in Makassar District with a density of 32.566 people/km2 at a rate of 32.566 people/km². population growth of 1.29% per year (“Kota Makassar Dalam Angka,” 2020). Meanwhile, data from IUWASH (2021) states that as many as 317,317 houses in Makassar City have permanent healthy latrines equipped with septic tanks.

From the explanation above, it is necessary to evaluate the processing unit at the Makassar Nipa-Nipa IPLT on the technical aspect to find out how to maximize the sludge treatment at this IPLT, then on the financial aspect to find out how much investment and investment feasibility is in maximizing the performance of the IPLT unit, and evaluation of the institutional aspects to determine the driving and inhibiting factors in order to obtain strategies and policies that can be applied in the operation of the Makassar Nipa-Nipa IPLT so that the IPLT operation can be carried out in accordance with the SOP.

The construction of the IPLT is one of the planned efforts to improve the treatment and disposal of waste that is friendly to the environment and also examines the characteristics of the effluent of sewage sludge. 68 of 2016 so as not to pollute the environment. Therefore, this research has the title "Performance Evaluation of Nipa-Nipa Sludge Treatment Plant (IPLT) in Makassar".

Fecal sludge sent to treatment plants has a wide range of properties. Due to a lack of analytical capacity for characterization and monitoring at many treatment plants, it is difficult to adapt treatment process operations accordingly (Ward et al., 2021).

The purpose of this study is to examine the performance of the processing unit at the Makassar Nipa-Nipa IPLT so that it is known which processing unit needs rehabilitation, to conduct a financial analysis regarding the feasibility of investing in the rehabilitation of the Makassar Nipa-Nipa IPLT unit with 3 analytical methods, and to determine the institutional management strategy in the development Institutional UPTD PAL Makassar based on the results of FFA (Force Field Analysis) analysis.

METHOD

The method used to evaluate the technical aspects is a comparison between the design criteria of planning and the design of existing criteria. Furthermore, for the evaluation of aspects using the NPV (Net Present Value) method, the BCR (Benefit Cost Ratio) method, and the IRR (Internal Rate of Return) method to determine the economic feasibility of the existing and post-rehabilitation IPLT. Then the institutional aspect to analyze the management and operation of the IPLT using the FFA (Force Field Analysis) method so that a strategy can be obtained to develop the institutional form of UPTD PAL Makassar as the manager of the current Nipa-Nipa IPLT.

Data collection

Data were collected from primary and secondary data. Primary data includes:

a. Laboratory tests of wastewater quality (TSS, BOD, COD, Oil & Fat, Ammonia, pH, and Total Coliform) at each Nipa-Nipa Makassar IPLT treatment unit as a basis for evaluation on technical aspects.

b. Interview about the current institutional condition of the Makassar IPLT Nipa-Nipa to determine the internal and external factors that support the FFA analysis. Interviews were conducted with UPTD PAL employees related to the management and operation of IPLT.

Secondary data includes:

a. Existing data from the Nipa-Nipa IPLT Makassar in the form of:

1) Physical conditions in the form of the dimensions of each processing unit at the Nipa-Nipa IPLT.

2) The existing condition is in the form of completeness and damage to the current Nipa-Nipa IPLT processing unit.

b. The number of trucks entering the IPLT per day to determine the flow of mud entering the IPLT per day.

c. The number of IPLT operational staff as the target in the interview for primary data needs.

d. IPLT Nipa-Nipa financial reports regarding community retribution, operating and maintenance costs, as well as other income and expenditure data as a basis for calculating financial aspects.

Data analysis

After collecting primary and secondary data, analysis is then carried out. Then the results of data analysis are used to evaluate the three aspects, namely technical, financial, and institutional. The evaluation is carried out by comparing the results of primary or monitoring data and secondary data with standards, guidelines, manuals and SNI, both technical and non-technical.

In this study, the method used to analyze the technical aspects is the calculation and comparison method, namely calculating the feasibility of the dimensions of the current IPLT processing unit and comparing them with the dimensions of the processing unit in the design criteria. Meanwhile, to analyze the financial aspect, the NPV, BCR, and IRR analysis methods are used to calculate the financial feasibility. And to analyze the institutional aspects, the FFA analysis method is used to obtain strategies that can be used to develop institutional forms at the current UPTD PAL Makassar City.

The following is the formula used in this research:

Area of anaerobic pond

A_a= = (3.1)

Where:

Aa = area of anaerobic pond, m²

Da = depth of anaerobic pond, m

Li = influent BOD, g/ m³

Q = discharge, m³/day

λv = volumetric BOD load (g/m³ days)

θa = hydraulic retention time in the pond (days)

Hydraulic Time Retention

θa = (3.2)

Net Present Value (NPV)

(3.3)

Benefit Cost Ratio (BCR)

(3.4)

Internal Rate of Ratio (IRR)

(3.5)

RESULTS AND DISCUSSION

A. Technical Aspects

Evaluation of the IPLT unit is carried out to determine the processing capacity of each unit which can be compared with the design criteria so that it can be seen whether the operation of this unit has been maximized or not. From the results of this evaluation, it can also be seen what actions can be taken to maximize the IPLT unit so that it can treat sludge according to its needs.

1. Imhoff tank unit

Imhoff tank function to separate the solids that can settle with the liquid contained in the feces. The tank is divided into two compartments (rooms) which are partitioned. The upper middle compartment functions as a settling/ sedimentation room (settling compartment) and the lower compartment functions as a processing room (digestion compartment).

Judging from the dimensions of the existing Imhoff tank, namely W x L x H = 4.5m x 4.5m x 4.5m, with an Imhoff capacity of around 20-25 m3/day if adjusted to the design criteria, the depth of the Imhoff tank is still lacking. And if it is operated again, this Imhoff tank will require a fairly expensive cost for rehabilitation whereas if you look at the current conditions, the sewage treatment system with the Imhoff tank has begun to be abandoned because the incoming sewage sludge is not continuous so that it can cause blockages and that is what happened in the current Nipa-Nipa IPLT, so that if forced, the blockage will still occur again, plus in this IPLT there is already an SSC unit with more or less the same function.

The recommendation for the imhoff tank unit is that the imhoff unit should no longer be used in the Makassar City sewage treatment system, because the characteristics of Makassar City sewage entering the desludging tank mostly consist of sand so that it will make it difficult to drain, and the imhoff unit is estimated to no longer be able to accommodate sewage sludge. that enter with the existing dimensions.

2. Pool Solid Separation Chamber (SSC)

SSC is an alternative for concentration units. The working principle is very simple because it only relies on a physical process for the separation of solids from sewage sludge. After separation, irradiation is carried out using sunlight as disinfection and wind for reducing humidity or drying. Solid Separation Chamber serves to separate solids and liquids from domestic wastewater. Sludge that is spread evenly on the SSC media will experience a separation between the solids at the bottom and the liquids at the top. Some of the liquid can be separated from the fecal sludge through the infiltration process on the SSC media, then the separated liquid is further processed in the stabilization unit contained in the IPLT. Meanwhile, the solids that have been drained are further dried in the sludge drying unit.

Judging from the existing dimensions of the SSC pond, if it is adjusted to the design criteria for the planning of the SSC pond, the correct results are obtained, only if you look at the current operation of the Nipa-Nipa IPLT where the SSC pond is used as an IPLT inlet pond, the existing dimensions of the SSC pond are still very small. Seeing the capacity per unit inlet of the SSC pond is only³with a sedimentation zone volume of 4.56 m³and the average discharge of mud entering the IPLT is³/ day, it can be seen that the capacity of this SSC unit is still very small. With this existing condition, it can be estimated that only 1 truck of feces per day can be filled.

In addition, judging from the operation of the SSC unit, it is still not in accordance with the existing SOP and with the design criteria above, where the minimum residence time is 3-5 days for the deposition process so that the resulting cake is cooked. Even in the design criteria in accordance with the Regulation of the Minister of Public Works and Public Housing Number 4 of 2017 Attachment II, 2017, the cake drying time can reach 5-12 days, so the operation is still not appropriate. Where when the fecal sludge enters the SSC unit, it is directly flowed to the anaerobic unit by only filtering solids with a size large enough in this SSC unit. This unit is also not equipped with a roof so that rainwater becomes an obstacle for the process of drying/ reducing the amount of water in the fecal during the rainy season.

Furthermore, the collection of cooked cakes which should be taken every day and brought to the SDB unit is also not carried out, because the process carried out at the SSC unit only filters coarse solids in the form of garbage with a size large enough then the waste will be cleaned manually by the operator, plus for the existing condition, the pipe that was supposed to drain the mud from the SSC unit to the SDB unit was clogged and was no longer in operation.

From the evaluation results above, recommendations can be given for the SSC unit at the Nipa-Nipa IPLT, namely re-operating the existing SSC unit with the aim of increasing the processing capacity and also adding a roof to the SSC unit considering that one of the functions of this SSC unit is for the separation of mud with a certain residence time so that there will be changes in the quality of the mud if the rainy season with the same residence time, it is better to make a roof for this unit. In addition, the operation is adjusted to the existing SOP so that it can maximize the performance of the SSC unit and the SDB unit can also be operated again.

3. Anaerobic Ponds

Anaerobic ponds are effectively used to treat wastewater containing high solids, where these solids will settle to the bottom of the pond and be digested anaerobically. The supernatant liquid that has undergone the process is flowed into the facultative pond for further processing.

The successful operation of an anaerobic pond depends on the balance between acid-forming microorganisms and methane bacteria, so the temperature must be greater than 15ºC and the pH greater than 6. Under these conditions, the accumulation of sludge in the pond is low so that removal (dredging) of sludge is necessary when the pond is halfway full (3-5 years). At <15ºC the anaerobic pond only functions as a sludge storage tank.

Parameter	Unit	Size	Source
Pond Depth	m	2 - 5	Duncan Mara, 1976
Removal Efficiency BOD₅	%	50 - 85	Metcalf & Eddy, 1991
Removal Efficiency SS	%	50 - 80	NJ Horan, 1990
Detention Time	Days	20- 50	Metcalf & Eddy, 1991
Temperature	ºC	15 - 30	Metcalf & Eddy, 1991
Pond Size	Ha	0.2 - 0.8	Metcalf & Eddy, 1991
BOD₅ Loading	Kg/ha,day	224.2 - 560.5	Metcalf & Eddy , 1991
SS effluent	mg/l	80 - 160	Metcalf & Eddy, 1991
pH	-	6.5 - 7.2	Metcalf & Eddy, 1991
Volumetric Loading	grBOD/m³/day	100 - 300	Duncan Mara, 1976

Thus T = 30,2 ^oC,

λv = 350 g/m³.day

b. Area of anaerobic pond

1) Area of pond

Based on equation 3.1:

A_a=

= m²

= 395,45 m²

2) Ratio of length to width (3:1)

(3L)(L) = 395,45 m²

3L² = 395,45 m²

L² = 131,82

L = √131,82

L = 11,48 à 11m

P = 33m

A’ = 363 m²

3) Hydraulic time retention

Based on equation (3.2) teh result of hydraulic time retention is 28.25 days (according to the design criteria, >1 day)

Anaerobic Pool II

4) Volumetric BOD load value (λv)

The value of λv will increase with increasing temperature. The value of λv can be seen from Table 2.

Thus T = 30,1 ^oC,

λv = 350 g/m³.days

5) Area of anaerobic pond

Area of pond

Based on equation 3.1:

A_a=

= m²

= 167,488 m²

Ratio of length to width (3:1)

(3L)(L) = 167,488 m²

3L² = 167,488 m²

L² = 55,83

L = √55,83

L = 7,47 à 7m

P = 21m

A' = 147 m²(in accordance with the

existing area)

6) Hydraulic retention time

Based on equation (3.2) teh result of hydraulic time retention is 11,96 days (according to the design criteria, >1 day)

Based on the existing area of each, which is 190.61m² and the area that should be 363m²from the calculation of the area in the anaerobic pond I, the area is already according to the incoming BOD capacity, where in this IPLT it is made into two pools with a series position and when calculating the area of the anaerobic pond in the second pool with the incoming BOD load, it is also in accordance with the design criteria for the pool area, only if it is adjusted to the design criteria according to the Regulation of the Minister of Public Works and Public Housing Number 4 of 2017 Attachment II, 2017 where the depth of the anaerobic pond must be 2-5m, it means that by design, the existing anaerobic pond of the Nipa-Nipa IPLT still does not meet the design criteria. Moreover, for the volumetric BOD load still exceeds the design criteria.

As for the design criteria with retention time, it is also in accordance with the existing retention time with the amount of BOD that comes in, it's just that the operation of the anaerobic pond at the IPLT is still not in accordance with the design criteria where the minimum residence time is 3-5 days and according to Metcalf, Eddy, and Tchobanoglous (1991) detention time is 20-50 days where in the existing conditions there is no control over that time and as previously explained that the success of the operation of an anaerobic pond depends on the balance between acid-forming microorganisms and methane bacteria, so the temperature must be greater than 15ºC and the pH greater of 6. Under these conditions, the accumulation of sludge in the pond is low so that sludge removal (dredging) is required when the pond is half full (3-5 years). At <15ºC the anaerobic pond only functions as a sludge storage tank. While in operation there is no periodic check of temperature and pH, nor is mud dredging carried out periodically in the anaerobic pond at the Nipa-Nipa IPLT.

Recommendations can be given in the form of rehabilitation of the anaerobic pond by increasing the depth of the pond and operating the anaerobic pond in accordance with the existing SOPs to maximize the performance of the WWTP anaerobic pond and it is also necessary to drain the sludge and crust of the hardened sludge as a whole to stabilize it. anaerobic treatment system because physically it can be seen on the surface of the anaerobic pond there is mud that hardens caused by the drying process that occurs so that it covers part of the surface of the pond. In addition, it is also necessary to add a roof to the anaerobic unit considering how the anaerobic process works by utilizing microorganisms, so that excess sunlight will affect the performance of microorganisms, so it is necessary to add a roof for the two anaerobic pond units at the Nipa-Nipa IPLT.

4. Facultative ponds

Facultative ponds are the most common oxidation ponds. The main thing in this system is always followed by two or more maturation pools. Facultative ponds can be used for BOD removal. In the Regulation of the Minister of Public Works and Public Housing Number 4 of 2017 Attachment II, 2017 it is explained that the facultative pond functions to decompose and reduce the concentration of organic matter in the waste that has been treated in anaerobic ponds implementation of facultative pond planning is determined based on the surface BOD loading rate (λs, kg/Ha.day). The facultative pond planning is based on the design criteria listed in Table 3 below.

Parameter	Symbol	Quantity	Unit
Minimum retention time
T < 20⁰C	θ_f	5	T
T > 20⁰C		4	days
BOD reduction efficiency	Hp	70 - 90	%
Pond depth	D	1.5 - 2.5	meters
Ratio of length and width	P : L	(2-4) : 1	-
Draining period		5 - 10	years

Parameters	Unit	Size	Source
Pond Depth	m	0.9 - 1.5	Metcalf & Eddy, 1991
Removal Efficiency BOD₅	%	60 - 80	Metcalf & Eddy, 1991
Removal Efficiency SS	%	20 - 75	NJ Horan, 1990
Detention Time	Days	5 - 20	Metcalf & Eddy, 1991
Temperature	ºC	0 - 30	Metcalf & Eddy, 1991
Pond Size	Ha	0.8 - 4	Metcalf & Eddy, 1991
BOD5 Loading	Kg/ha,day	16.8	Metcalf & Eddy, 1991
pH	-	6.5 - 10.5	Metcalf & Eddy, 1991
Surface Loading	grBOD/Ha/day	100 - 424	Duncan Mara, 1976

Parameter	Unit	Quantity	Source
period	Day	10 - 15	Syed R. Qasim, 1985
Moisture of effluent sludge	%	60 - 70	Syed R. Qasim, 1985
Sludge solid content	%	30 - 40	Syed R. Qasim, 1985
Solid capture	%	90 - 100	Syed R. Qasim, 1985
Solid loading	kg/m².day	0.27 - 0.82	Syed R. Qasim, 1985
Mud thickness	mm	200 - 300	Metcalf & Eddy, 1991
Coefficient of uniformity	-	< 4	Metcalf & Eddy, 1991
Effective size	mm	0.3 - 0.78	Metcalf & Eddy, 1991
Slope	%	> 1	Metcalf & Eddy, 1991
Ratio of length: width	m	6: 6 - 30	Metcalf & Eddy, 1991

Table 7

Comparison of COD Allowance Percentage

No	Processing Unit	Existing			Design Criteria
		%Removal COD	[COD] (mg /L)		%Removal COD*	[COD] (mg/L)
		%Removal COD	Influent	Effluent	%Removal COD*	Influent	Effluent
1	Solid Separation Chamber	19%	40816.6	33170.3	17%	40816.60	3387 7.78
2	Anaerobic Pool 1	57%	33170.3	14375.15	65%	33877.78	11857.22
3	Anaerobic Pool 2	97%	14375.15	397.46	65%	11857.22	4150.03
4	Facultative Pool	33%	397, 5	265.6	95%	4150.03	207.50
5	Maturation Pond	13%	265.6	230.5	80%	207.50	41.50

Source: Calculation Results, *(Pratiwi, 2019)

Table 8

Comparison of the Percentage of TSS Allowance

No	Treatment Unit	Existing			Design Criteria
		%Removal TSS	[TSS] (mg/L)		%Removal TSS*	[TSS] (mg/L)
		%Removal TSS	Influent	Effluent	%Removal TSS*	Influent	Effluent
1	Solid Separation Chamber	60%	3205	1290	70%	3205.00	961.50
2	Anaerobic Pool 1	32%	1290	877	80%	961.50	192.30
3	Anaerobic Pool 2	94%	877	52.5	80%	192.30	38.46
4	Facultative Pool	63%	52.5	19.5	85%	38.46	5 ,77
5	Maturation Pool	33%	19.5	13.0	80%	5.77	1.15

Source: Calculation Results, *(Pratiwi, 2019)

Table 9

Details Benefit-Cost Planning

Parameter	Cost	Description
Cost
Unit Repair Cost	IDR 645.484.000	The 1st year
Non-Civil servants employee salary	IDR 68.400.000	Starting from the 2nd year
Collection fee	IDR 687.180.000	Starting from the 2nd year
Fleet maintenance costs	IDR 82.134.000	Starting from the 2nd year
Unit maintenance costs	IDR 6.000.000	Starting from the 2nd year
Office administration costs	IDR 55.928.000	Starting from the 2nd year
Total cost after repair	IDR 899.642.000	Starting from the 2nd year
Benefit
Levy for desludging per septic tank	Rp 624.000.000	Starting from the 2nd year
Retribution for desludging per truck	Rp 30.000.000	Starting from the 2nd year
Total benefit	Rp 654.000.000	Starting from the 2nd year

Source: Result of Calculation

Table 10

Calculation of NPV with DF 10% (Planning)

Year	Cost	Benefit	NB	DF 10%	Present Value
Year	Cost	Benefit	NB	DF 10%	PV cost	PV benefit
1	Rp 655.166.260	Rp -	-Rp 655.166.260	0,909	Rp 595.605.691	Rp -
2	Rp 926.631.260	Rp 673.620.000	-Rp 253.011.260	0,826	Rp 765.810.959	Rp 556.710.744
3	Rp 940.125.890	Rp 799.613.100	-Rp 140.512.790	0,751	Rp 706.330.496	Rp 600.761.157
4	Rp 953.620.520	Rp 928.941.600	-Rp 24.678.920	0,683	Rp 651.335.646	Rp 634.479.612
5	Rp 967.115.150	Rp 1.061.605.500	Rp 94.490.350	0,621	Rp 600.502.418	Rp 659.173.492
6	Rp 980.609.780	Rp 1.197.604.800	Rp 216.995.020	0,564	Rp 553.528.656	Rp 676.016.688
7	Rp 994.104.410	Rp 1.336.939.500	Rp 342.835.090	0,513	Rp 510.132.748	Rp 686.061.358
8	Rp 1.007.599.040	Rp 1.479.609.600	Rp 472.010.560	0,467	Rp 470.052.388	Rp 690.248.798
9	Rp 1.021.093.670	Rp 1.625.615.100	Rp 604.521.430	0,424	Rp 433.043.394	Rp 689.419.492
10	Rp 1.034.588.300	Rp 1.774.956.000	Rp 740.367.700	0,386	Rp 398.878.576	Rp 684.322.375
Total					Rp 5.685.220.973,56	Rp 5.877.193.715,98

Source: Result of Calculation

Depends on equation 3.3:

NPV1 = Rp 191.972.742,42

Table 11

Calculation of NPV with DF 12% (Planning)

Tahun	*Cost*	*Benefit*	NB	DF 12%	*Present Value*
Tahun	*Cost*	*Benefit*	NB	DF 12%	*PV cost*	*PV benefit*
1	Rp 655.166.260	Rp -	-Rp 655.166.260	0,893	Rp 584.969.875	Rp -
2	Rp 926.631.260	Rp 673.620.000	-Rp 253.011.260	0,797	Rp 738.704.767	Rp 537.005.740
3	Rp 940.125.890	Rp 799.613.100	-Rp 140.512.790	0,712	Rp 669.163.039	Rp 569.148.810
4	Rp 953.620.520	Rp 928.941.600	-Rp 24.678.920	0,636	Rp 606.043.080	Rp 590.359.181
5	Rp 967.115.150	Rp 1.061.605.500	Rp 94.490.350	0,567	Rp 548.767.109	Rp 602.383.471
6	Rp 980.609.780	Rp 1.197.604.800	Rp 216.995.020	0,507	Rp 496.807.432	Rp 606.743.863
7	Rp 994.104.410	Rp 1.336.939.500	Rp 342.835.090	0,452	Rp 449.682.350	Rp 604.763.534
8	Rp 1.007.599.040	Rp 1.479.609.600	Rp 472.010.560	0,404	Rp 406.952.353	Rp 597.589.501
9	Rp 1.021.093.670	Rp 1.625.615.100	Rp 604.521.430	0,361	Rp 368.216.614	Rp 586.213.102
10	Rp 1.034.588.300	Rp 1.774.956.000	Rp 740.367.700	0,322	Rp 333.109.743	Rp 571.488.328
Total					Rp 5.202.416.362,49	Rp 5.265.695.529,40

Source: Result of Calculation

Table 12

Driver and Barrier Factors

No	Driver Factors	No	Barrier Factors
Strengths		Weaknesses
D1	Institutional structure	H1	Infarctional do not working optimally
D2	Clear work plan	H2	Human resources not yet adequate
D3	SOPs are clear and easy to apply	H3	The IPLT management budget is not sufficient
D4	There is training for operators on SOPs	H4	Implementation of the authority, duties, and responsibilities of employees is not maximized
D5	Routine monitoring and evaluation activities	H4
D6	No complaints from the public about pollution	H5	No sanctions yet from leaders regarding the application of SOPs
Opportunities (Opportunities)		Threats (Threats)
D7	There is support for guidance in the management of IPLT	H6	The community does not understand the importance of using a septic tank with SNI
D8	There are income opportunities apart from the Regional Government
D9	There is a commitment from the Regional Government to sanitation
D10	There is involvement of other agencies in the management IPLT	H7	Target service at PERWALI has not been achieved
D11	There is socialization to the community about the use of septic tanks with SNI	H7	Target service at PERWALI has not been achieved

Source: Results of the analysis

CONCLUSION

The results of the evaluation of the processing unit at the Nipa-Nipa IPLT Makassar indicate that the existing processing unit can still be operated and still able to reduce levels of contaminants and below the quality standard with improvements to several processing units without additional units. Where the treatment units that need improvement are anaerobic ponds I - II which need to increase the height of the pond, SSC ponds and anaerobic ponds I - II which need to be roofed and the closure of the Imhoff tank pond. The rest only needs to be maximized in the post-repair IPLT operation in accordance with the existing SOP so that the processing unit can maximize its processing.

The results of the evaluation on the financial aspect using the NPV (Net Present Value) method, the BCR (Benefit Cost Ratio) method, and the IRR (Internal Rate of Return) method indicate that in the existing condition, the IPLT still suffers losses in its management and operation. After the analysis, the financial condition of the IPLT management can recover and make a profit if there are additional customers by 17% per year from the number of existing customers.

As for the institutional aspect, the results of the evaluation using the FFA (Force Field Analysis) method show that after improvements have been made to IPLT and after the restoration of financial conditions at this IPLT, it is possible for institutional development from the UPTD form to become an institution with the Financial Management Pattern of the Public Service Agency. Regions (PPK-BLUD) which operationally provide direct services to the community and prioritize the principles of efficiency and productivity.

Referring to the results of the evaluation and analysis of the research, for further research it is recommended that there be an analysis for other possible sources of income in this IPLT by looking at the existing business opportunities so that it is possible to achieve faster financial recovery for the management (operation and maintenance) of all aspects involved related in this Nipa-Nipa IPLT.

REFERENCES

Anggraini, F. (2011). Aspek Kelembagaan pada Pengelolaan Tempat Pemrosesan Akhir Sampah Regional. Jurnal Permukiman, 6(2), 78-84. Google Scholar

Chong, J., Abeysuriya, K., Hidayat, L., Sulistio, H., & Willetts, J. (2016). Strengthening local governance arrangements for sanitation: case studies of small cities in Indonesia. Aquatic Procedia, 6, 64–73. Scopus

Ginting, N. (2007). Teknologi pengolahan limbah peternakan. Teknologi Pengolahan Limbah Peternakan. Google Scholar

Kota Makassar dalam Angka. (2020). Retrieved from https://makassarkota.bps.go.id/publication/2020/04/27/bc3a47054c386bac66a38333/kota-makassar-dalam-angka-2020.html

Kristanto, I. (2004). Ekologi Industri. Ekologi Industri. Penerbit: ANDI. Yogyakarta. Google Scholar

Lukman, R. R., Pratiwi, Y. E., & Rosdiana, R. (2021). Evaluasi Teknik Operasional dari Kinerja Instalasi Pengolahan Lumpur Tinja di Kota Kendari. Jurnal TELUK: Teknik Lingkungan UM Kendari, 1(1), 1–7. Google Scholar

Metcalf, L., Eddy, H. P., & Tchobanoglous, G. (1991). Wastewater engineering: treatment, disposal, and reuse (Vol. 4). McGraw-Hill New York. Google Scholar

Muthawali, D. I. (2013). Analisa COD dari Campuran Limbah Domestik dan Laboratorium di Balai Riset dan Standarisasi Industri Medan. -, 5(01), 1–13. Google Scholar

Pangestu, M. P. (2021). Pengaruh Keberadaan Ipal Komunal Terhadap Area Risiko Sanitasi Tinggi Sektor Air Limbah Di Kabupaten Sleman. Google Scholar

Qasim Syed, R. (1985). Waste Water treatment plants planning, Design, and operation. The University of Texas at Arlington, USA. Google Scholar

Rahmawati, (2021). Evaluasi Pengelolaan TPA Regional Kebon Kongok Kabupaten Lombok Barat Provinsi NTB. ITS. Surabaya. Google Scholar

Siregar, S. A. (2005). Instalasi pengolahan air limbah. Kanisius. Google Scholar

Ward, B. J., Andriessen, N., Tembo, J. M., Kabika, J., Grau, M., Scheidegger, A., … Strande, L. (2021). Predictive models using “cheap and easy” field measurements: Can they fill a gap in planning, monitoring, and implementing fecal sludge management solutions? Water Research, 196, 116997. Scopus

Temperature (^oC)	Volumetric Load (g/ m³.day)	BOD Removal (%)
< 10	100	40
10 – 20	20T – 100	2T + 20
20 – 25	10T – 100	2T + 20
> 25	350	70

No	Treatment Unit	Existing			Design Criteria
		%Removal BOD	[BOD] (mg /L)		%Removal BOD*	[BOD] (mg/L)
		%Removal BOD	Influent	Effluent	%Removal BOD*	Influent	Effluent
1	Solid Separation Chamber	8%	10689.95	9886.34	50%	10689.95	5344.98
2	Anaerobic Pool 1	58%	9886.34	4187, 19	70%	5344.98	1603.49
3	Anaerobic Pools 2	97%	4187.19	138.86	70%	1603.49	481.05
4	Facultative Pools	37%	138.86	88.15	95%	481.05	24.05
5	Pools Maturation	13%	88.15	76.99	80%	24.05	4.81