**1. Introduction**

Waste managemen<sup>t</sup> is a complex issue in developing countries, from mega-cities to small towns and villages, and has been on the priority list of successive governments, local authorities, and international donors in recent years [1,2]. This issue creates one of the most critical health and environmental concerns confronting many administrators [3–5]. In many constitutions, it is the responsibility of the local governmen<sup>t</sup> to provide infrastructure; including power and water supplies, public transportation, telecommunications, security, and waste managemen<sup>t</sup> facilities. As documented in the policy guidelines of the Federal Ministry of the Environment (2005) on Solid Waste Management, urban solid waste managemen<sup>t</sup> in Nigeria is constitutionally the responsibility of the third tier of government, that is, the local governmen<sup>t</sup> [4]. However, this tier of governmen<sup>t</sup> has not committed the necessary financial, material, and human resources to waste managemen<sup>t</sup> to fulfil their responsibility [6].

The actual performance of the public sector in Nigeria has left much to be desired not only in the waste managemen<sup>t</sup> sector but in many of the state-owned enterprises which are not responsive to the changing requirements of a growing and dynamic economy and do not seem to possess the necessary tools for effective service delivery [7]. Solid waste managemen<sup>t</sup> institutions in Nigeria are crippled by the lack of a comprehensive legislative framework for effective solid waste management, overlapping functions, lack of funding, poor implementation of environmental policy, vested interests and corruption, and a technological deficit to match the rate at which solid waste is being generated [4,8,9]. The people

also have a part to play in e ffective SWM, as poor waste disposal habits, corruption, refusal to pay for waste collection services and bad work attitudes hinder the e fforts of the local governmen<sup>t</sup> in providing an e ffective waste managemen<sup>t</sup> service in Nigeria [4,6]. Given the failure of the public sector in e ffective service delivery, many have viewed the involvement of the private sector in public infrastructure provision as a way forward. This approach has gained global prominence with varying degrees of success in di fferent countries and in di fferent sectors of the economy [10–15].

In view of the challenges associated with providing e fficient and sustainable waste managemen<sup>t</sup> in most urban settings in Nigeria, this paper discusses the current state of public-private partnerships (PPPs) in urban solid waste managemen<sup>t</sup> alongside managemen<sup>t</sup> practices and strategies. The following research questions have been drawn from the aim: In what ways can and have the private sector partnered with the public sector for more e fficient service delivery? How have collaborations between the public and private sectors benefited waste managemen<sup>t</sup> in Nigeria? What lessons can be learnt from other developing countries with relative success in jointly provided waste managemen<sup>t</sup> services? Four cities—Lagos, Ibadan, Abuja and Port Harcourt—have been chosen from three geopolitical zones in Nigeria based on their demographic and socio-economic features as a reflection of the Nigerian situation, and because of the availability of literature on these cities.

#### **2. Private Sector Involvement in Infrastructure**

Private sector involvement in infrastructure development has gained significance over the years in developed and developing countries alike [16]. The local governmen<sup>t</sup> typically represents the public partner at the national, state, or local agency level while the private partner can be a privately-owned enterprise or consortium of businesses with a particular specialisation whose main aim is profit realization [17] defines public-private partnerships (PPPs) as a contract between a public authority and one or more private operators to transfer the control of a good or a service currently provided by the public sector, either in whole or in part, to the private operators.

#### *2.1. Forms of Private Sector Involvement in Infrastructure*

Private sector involvement (PSI) in infrastructure development has been described as a spectrum given that it can take a number of forms, depending on the degree of risk shared by the private and public sectors and the duration of the contract. In cases where the governmen<sup>t</sup> merely outsources the provision of a basic service to the private sector, the governmen<sup>t</sup> retains ownership of the assets involved and a larger portion, if not all, of the risk involved. Conversely, in divestitures or privatisations, the governmen<sup>t</sup> transfers the control of an asset either partially or in full to the private sector [18,19]. PPPs are considered as alternatives to full privatisation in which there is a substantial extent of risk sharing between the public and private sectors [20,21]. Table 1 gives a brief description of the basic forms of private sector involvement practiced around the world.


**Table 1.** Description of types of PSI with examples from other countries.

Table 1 above is not an exhaustive list of the forms of PSI that are practiced around the world. For example, the variations of the BOT contract (e.g. Build-Own-Operate, Build-Operate-Manage-Transfer), and the Private Finance Initiative (PFI) practiced in the UK are not included. Although BOT contracts and concessions share similar characteristics, they differ in the mode in which the private partner is paid. In many concession contracts, the private partner recovers its investment from the users of the service by imposing tolls, fees, etc., while BOT contracts usually involve the public sector paying a bulk fee to the private partner [21,23]. Also, because of the complexity of PSI projects, different means of classifying PSI exist, based on how the private partner recoups costs [18], and based on the nature of the service provided and the degree of risk sharing [21].

#### *2.2. Success Factors of Private Sector Involvement in Infrastructure Development*

Over 4000 public infrastructure projects have been implemented in collaboration with the private sector between 1990 and 2007, and a number of successes and failures have been recorded [19]. Many researchers have sought to find commonalities among PSI projects that contributed to their success or failure. One approach that has been used widely, is finding the critical success factors (CSFs) that attempt to delineate the most crucial areas that are required to ensure managemen<sup>t</sup> success [24].

While the CSFs for PPP projects are fairly consistent around the world [25–27], the ranking of individual CSFs in developed and developing nations highlight the di fferences in their political and socio-economic climates. The results presented in [28] and [29] show similar CSFs for the implementation of PPP projects in Nigeria.

In Nigeria for example, the failures recorded by the state owned waste managemen<sup>t</sup> bodies in providing non-rivalled and non-exclusive SWM service, is one of the main reasons for involving the private sector in SWM operations [4].

#### **3. Private Sector Involvement in SWM in Nigeria**

The Federal Ministry of Environment is responsible for environmental protection, natural resources conservation and sustainable development in Nigeria and e ffective waste managemen<sup>t</sup> is one of its cardinal focuses. In 2005, a set of policy guidelines on solid waste managemen<sup>t</sup> was developed by the Federal Ministry of Environment. The policy guidelines set out general objectives for solid waste managemen<sup>t</sup> in Nigeria and defined the roles and responsibilities of the governmen<sup>t</sup> at the federal-, state- and local-government level. The following four solid waste managemen<sup>t</sup> options were recommended within the policy guidelines:


Like much of Nigeria's environmental laws and policies, the policy guidelines have never been effectively implemented, and there has not been any further development at the federal level of private sector involvement in solid waste managemen<sup>t</sup> [30].

#### *3.1. Private Sector Involvement in Solid Waste Management in Abuja, Federal Capital Territory*

Abuja was created in 1976 by a decree by the then military head of state, General Murtala Mohammed. A master plan was developed for the city in 1979 that included provision of waste managemen<sup>t</sup> infrastructure that could cater for a steady increase in population. However, due to rapid expansion, the population of Abuja now exceeds the original design capacity with a projected population of about 5.8 million people by 2026 (Federal Ministry of the Environment, 2005). Hence, waste managemen<sup>t</sup> infrastructure has not been developed in phase with city growth and the environmental challenges of highly populated cities like Lagos are also being experienced in Abuja [31].

In Abuja, the Abuja Environmental Protection Board (AEPB) is responsible for the managemen<sup>t</sup> of solid waste and is the principal authority for waste collection and disposal in the city. The area councils and satellite towns in the city were delineated into 22 lots for the purpose of daily waste collection from households in the councils. Collection of solid waste is contracted to 12 private operators in a concession agreemen<sup>t</sup> which runs for a minimum of three years. The AEPB, the Abuja Investment Company and a Ukrainian firm, entered into a joint-venture agreemen<sup>t</sup> for waste managemen<sup>t</sup> activities in Abuja. Under the agreement, the AEPB and the Ukrainian technical partners shared the cost of procuring 50 compacting trucks and 12 street sweepers, with the AEPB contributing 20 percent of the funds. Figure 1 shows the distribution of waste managemen<sup>t</sup> vehicles operating in Abuja and it can be seen that over 75% of operational waste managemen<sup>t</sup> equipment is private-owned.

**Figure 1.** Distribution of waste collection, transportation and disposal vehicles in Abuja. *Source*: [32].

It is evident from Figure 1 that the private sector owns more operational vehicles than the public sector in Abuja due to factors such as availability of capital for procurement and maintenance of these vehicles. However, e fficient waste managemen<sup>t</sup> is still a challenge in Abuja as the service provided is usually restricted to the major districts in the city. Overflow of waste into the roads due to infrequent collection of solid waste from the designated storage sites or communal bins has been reported in some satellite towns and city suburbs.

Given the current state of waste managemen<sup>t</sup> in the city, measures should be put in place to strengthen waste governance by integrating the private public partnership and informal sector models for more e ffective waste collection and disposal. This approach is expected to help reduce challenges that arise as a result of conflicts across agencies, while at the same time leveraging on the financial, technical and administrative capacity of the private sector for sustainable SWM in the city [33].

#### *3.2. Private Sector Involvement in Solid Waste Management in Lagos, Lagos State*

Lagos State is the economic capital of Nigeria and the largest, most diverse single settlement in the country [33]. While MSWM operations have been organized compared to other states, the managemen<sup>t</sup> of solid waste in Lagos State is still far from optimal. Though the Nigerian constitution charges the local governments with the responsibility of SWM, over time, the state governmen<sup>t</sup> has taken up the responsibility.

Continuous increase in population in many cities has led to an increase in the rate of waste generation that the public agencies could not manage. The agencies lacked the financial, technological, and skilled human capital to match the rate of waste generation. This led to streets getting dirtier and exposed Nigeria to global ridicule as Lagos, the largest city in the country, became infamous for being one of the dirtiest cities in the world after the Festival of Arts and Culture in 1977 [6,34]. Even with the institution of the Lagos State Refuse Disposal Board (LSRDB) and Lagos Waste Management Authority (LAWMA) in 1977 and 1991, respectively, the state of waste managemen<sup>t</sup> in Lagos did not improve as the medians of roads in the state were still characterized by waste heaps, drains were clogged with waste and market places and many other public places were littered with solid waste [34–36].

Prior to the incorporation of the private sector, the e fforts of the governmen<sup>t</sup> had been deterred by issues such as lack of finance for capital investments and high operational costs associated with provision of waste managemen<sup>t</sup> service. Such problems were not peculiar to Lagos alone but were common in other states in the country. Other issues particular to the Lagos metropolis include tra ffic congestion which limited the number of trips collection vehicles could make per day, high rate of waste generation, unavailability of land, and rural-urban migration [37].

With 340 private sector participants (PSPs) registered in Lagos State alone, there has been an improvement in solid waste managemen<sup>t</sup> service delivery, especially in the aspect of waste collection. The PSPs introduced waste collection at the source (that is collection from door-to-door) and residents were billed according to the value of the property and the area in the state. Residents in high income areas are billed the highest and e fficiency of service delivery is reported to be highest in these areas as well [6,34]. An analysis of the state of waste managemen<sup>t</sup> in Lagos shows that more equipment has been made available for the collection and transportation of solid waste from the source to the disposal sites.

Private sector involvement in SWM in Lagos has progressed since it was first introduced formally under the LSRDB in 1985 till 1991 when LAWMA was created. The Table 2 below outlines the history of private sector involvement in SWM in Lagos from 1997 to 2017.



Source: [33].

While grea<sup>t</sup> strides have been made in the state [5], problems such as inadequate funding, cost recovery, unstable power supply, and tra ffic congestion militate against e ffective SWM in Lagos. Also, lack of continuity in implementing SWM policies prevents the full actualisation of the benefits of public-private partnerships: An example being the dissolution of LAWMA and the PSP scheme by the incumbent government. To replace them, the state governmen<sup>t</sup> recently awarded contracts to Visionscape Sanitations Solutions and its strategic partners for deployment of waste managemen<sup>t</sup> infrastructure. The transition has not been smooth, however, as the state of waste managemen<sup>t</sup> in Lagos has since deteriorated and waste is being dumped on the streets and along the road median.

#### *3.3. Private Sector Involvement in Solid Waste Management in Ibadan, Oyo State*

Ibadan is the capital of Oyo State and the third most populous city in Nigeria with 3,088,477 residents [38]. The city is one of the foremost commercial hubs in Nigeria alongside Kano and Onitsha. The Oyo State Solid Waste Management Authority (OYOMWA) is responsible for waste managemen<sup>t</sup> in the Ibadan metropolis. Managing the large volumes of waste generated in Ibadan has been a serious challenge for all stakeholders. Indiscriminate dumping of waste is widely practiced in the city resulting in waste heaps littering road sides and streets.

Private sector involvement in SWM in Ibadan dates as far back as 1994 when private contractors were involved in collection, transport, and disposal of solid waste [30,31]. In Oyo State, the private sector participation scheme suffered because of challenges with availability of capital for the purchase of equipment. Therefore, purchasing equipment for use such as trucks and tippers is always beyond the reach of the owners. The resultant effect of this constraint was that some firms also used their trucks for construction activities in order to maximize profit. Also due to financial constraints, the private firms are unable to purchase the necessary spare part replacements, pay staff salary and employ trained experienced manpower [39].

#### *3.4. Private Sector Involvement in Solid Waste Management in Port Harcourt, Rivers State*

Port Harcourt is the capital city of Rivers State and one of the most prominent cities in the southern region of Nigeria. Port Harcourt was initially established as a port-town during the colonial times but since the discovery of oil in Rivers State, the city has evolved into one of grea<sup>t</sup> economic and political importance. The city is home to 1,845,232 residents [38]; a number which is rapidly on the increase due to urbanization and rural-urban migration.

The Rivers State Waste Management Agency (RIMAWA) is responsible for solid waste managemen<sup>t</sup> in the state under the supervision of the state Ministry of Environment. The agency engages about 88 local vendors or contractors who provide services ranging from de-silting of creeks and canals, municipal waste collection, and dumpsite managemen<sup>t</sup> within Rivers State (RIMAWA, n.d.). The challenges of managing waste in Port Harcourt arose mainly with the uncontrolled and unplanned development of the city which resulted in overcrowding, unplanned road networks, and heaps of refuse littering various parts of the city [40]. House-to-house collection is limited to the elite areas of the city (e.g. Old GRA) while communal bins are provided in areas like Borokiri [41]. A study carried out by Stanley and Owhor [41] on 390 respondents in three neighbourhoods within the city showed that the frequency of collection also varied across the city with Ogbumnuabali enjoying more frequent collection than Borokiri and Elekahia. The above data points to the fact that waste collection is not uniform in the city even with the involvement of private contractors.

Comparing the state of solid waste managemen<sup>t</sup> in Lagos and Port Harcourt, it is evident that the latter is only beginning to explore the benefits of collaborating with the private sector for more efficient service delivery. Waste managemen<sup>t</sup> in Rivers State is still in its developmental stages and is mainly concerned with collection, transportation and disposal of solid waste. No attention has been given formally to waste minimization activities or the recovery of resources from the waste stream.
