While household toilets are only one part of the large challenge for the government, having liquid and solid waste management facilities, along with water delivery across the entire country, is a trickier one.
Prime Minister Narendra Modi launched the Swachh Bharat Mission in October 2014, setting the template in place for the way the National Democratic Alliance government would launch, promote and implement its social schemes on a grand scale.
The mission with two components - urban and rural - is to ensure an open defecation-free country by October 2, 2019.
That required, as rightly listed from the beginning, two essential tasks to be done.
The infrastructure had to be put in place - toilets in the households, and solid and liquid treatment and handling facilities at the back end.
And, then a more arduous task was at hand, ensuring a behavioural and social change.
The mission is well on its way on achieving one bit of it. When the programme started, 38.70 per cent rural households had toilets.
The government claims that 83.71 per cent have them now. Since 2014-15, 71.96 million toilets have been built, it claims. By all measures, this is a considerable achievement.
Interestingly, the government seems to have achieved this with much less money than it had envisaged.
While taking a loan from the World Bank, the government projected the rural end of the programme would require $22 billion, equivalent to Rs 147,400 crore (at Rs 65 to a US$), of which Rs 100,000 crore would come from the Central government.
In comparison, by 2017-18, the government had spent only Rs 37,000 crore and has allocated another Rs 15,400 crore for 2018-19. This adds up to just above half the projected expenditure.
Reports earlier raised doubts over how the targets might have been achieved even though the amount of subsidy provided by the government remained fixed at planned levels.
Government officials have told Parliament inadequate funding might be an obstacle to achieving targets in time.
They expected Rs 55,000 crore over 2017-19 but the government provided only Rs 32,300 crore, with the possibility of an additional Rs 10,000 crore being made available mid-year.
In fact, a target-oriented approach, critics have warned, might later lead to a partial repeat of the problems such schemes have faced in the past - toilets falling into disuse after a while.
The government on its part has just completed its first independent verification of its data in March 2018.
It claimed the data showed 77 per cent of households were found to have access to toilets and 93.4 per cent of the people who had access to toilets used them.
The study was done on a sample of 15 out of 168.5 million households in 6,136 villages.
In 2016, Kimberly M Noronha and Shubhagato Dasgupta of the Centre for Policy Research had investigated the weakness of such sample studies to assess the usage of toilets.
In their study they noted "survey instruments are designed to measure the presence of toilets, not their usage and reasons thereof.
"One of the key reasons for slippage back to open defecation is the fact that toilets are not functional - either they have not been maintained properly or essential services such as water supply to the toilets are problematic."
They quoted a sample study in 2016 of 7,500 households with toilets and said that of the toilets constructed in the surveyed households, 29 per cent were found to exist only on paper, and of those built, 36 per cent were considered unusable by the surveyed households.
The Parliamentary Standing Committee on Rural Development, which has reviewed the programme, has voiced concern over the infrastructure and resources being made available for the use of the constructed toilets.
And, the household toilets are only one part of the large challenge for the government.
Having liquid and solid waste management facilities, along with water delivery across the entire country, is a trickier one the government has been tackling.
And on top of that is the challenge of behaviour change, which cannot be quantified.
The Union government does spend 3 per cent of its Budget on outreach and education, expecting states to top that.
Naturally it is not within the capacity of a ministry or a programme to change the societal outlook of many who continue to associate handling human waste with oppressed scheduled castes.
That is the biggest test of the ambitious programme and one which setting targets does not help one way or the other.
Photograph: PTI Photo