For years, families along the Kisumu-Chemelil road in Mamboleo have lived with the ground trembling underfoot and the nagging fear that the next dynamite blast from a nearby quarry could bring their houses down.

That long-simmering grievance against Ndugu Transport Company Limited has now spilled into public view, forcing uncomfortable questions about environmental enforcement, corporate accountability and whether ordinary Kisumu residents are again being asked to absorb the costs of someone else’s development.

The firm operates a quarry along the Kisumu-Chemelil road in Mamboleo.

Residents say routine rock blasting sends vibrations through the ground strong enough to crack walls and weaken foundations.

They also cite an earlier incident in which flying rock struck a resident on the head and damaged nearby roofs, and they say repeated complaints lodged with the National Environment Management Authority office in Kisumu have produced no visible change.

A complaint has described the situation in blunt terms, alleging that the company has become a nuisance to both people and property in Mamboleo and appealing to the government to intervene before someone is seriously hurt.

The company at the centre of the complaint is no fly-by-night operator. Ndugu Transport traces its roots to October 1972, when Harbhajan Singh Sembi built the business from his personal savings into what has become a diversified quarrying, transport, precast concrete and building contracting operation.

Leadership has stayed firmly inside the family.

Harbhajan Singh Sembi remains Founder and Chairman, his son Manjeet Singh Sembi runs the business day to day as Managing Director and CEO, Jasminder Kaur Sembi oversees daily operations as a Director, Balraj Singh Sembi applies his engineering training as Chief Operating Officer, and Manveer Singh Sembi, an architect by training, sits on the board.

The firm markets itself as a fifty-year institution in the region’s construction supply chain, moving roughly a thousand tonnes of aggregate a day out of Mamboleo alone.

That history of longevity makes the present standoff more striking, because on paper Ndugu Transport has already made public commitments on exactly the issues residents are now raising.

Kisumu County records show that in October 2021, Managing Director Manjeet Singh Sembi personally attended a county subcommittee meeting on natural resources at the Grace Onyango Social Hall, convened after abandoned quarry pits were flagged as hazards linked to drowning risk, mosquito breeding and soil erosion.

Alongside other quarry operators, he commended the county’s engagement and pledged, on the record, to restore exhausted sections of the quarry and plant trees to reduce the environmental hazard to surrounding communities. Five years on, residents say the blasting, not the restoration, is what defines their daily experience of the firm.

Court records add a further layer that residents may not even be aware of. In Frederick Sewe versus Ndugu Transport Company Limited, an employment dispute that ran from the Employment and Labour Relations Court in Kisumu in 2018 through to the Court of Appeal in February 2024, the company’s own transport and logistics manager testified under oath that trucks leaving its quarry were suspected of being overloaded, and that a loader had been summarily dismissed over the allegation.

Both courts ultimately ruled against the company on procedural grounds, and buried in that judgment is a detail with implications well beyond one worker’s dismissal: the company’s own witness confirmed there was no weighbridge at the quarry at all. Neither court could find that the alleged overloading had been proven, precisely because the firm had no instrument to measure it.

A separate 2020 Court of Appeal case, brought by driver Barrack Musumba Oluoch over an unlawful termination dating to 2014, produced a similar outcome against the company.

A 2006 arbitration under the Trade Disputes Act, resolved only after a collective agreement was signed with the Kenya Quarry and Mine Workers’ Union, points to a longer history of friction between management and the workforce that keeps the quarry running.

“The appellant’s own witness testified that there was no weighbridge at the quarry. How, then, could the appellant prove that the trucks were being overloaded?” — Court of Appeal, Ndugu Transport Company Limited v Sewe, February 2024

None of this proves the specific claims now being raised in Mamboleo about blasting damage. But it does establish, from the company’s own court filings and witness testimony rather than from anonymous complaints, that basic monitoring infrastructure that any well-run quarry would use to police its own operations has been absent before.

If a weighbridge was missing for measuring truck loads, residents are entitled to ask what systems, if any, govern blast design, vibration limits and flyrock containment at the same site.

The timing could not be more pointed. Kisumu County’s entire quarry sector is under fresh and unusually forceful scrutiny after four siblings, aged between eight and fifteen, drowned in February 2026 in an abandoned, water-filled quarry pit in Kanyakwar, a tragedy that Governor Anyang’ Nyong’o called preventable.

The Governor responded with an immediate county-wide suspension of all quarrying, murram extraction and sand harvesting, and ordered NEMA, the County Department of Environment and the Office of the County Commissioner to form a joint task force to map every active and abandoned quarry in the county, audit compliance and take legal action against operators found in breach. Deputy Governor Mathew Owili has since said the audit will feed into tighter licensing rules, mandatory rehabilitation bonds and clearer safety obligations across the industry.

An active, high-volume operation like the Mamboleo quarry sits squarely inside the scope of that exercise, whatever the outcome of the specific blasting complaints.

Quarrying is not optional for a country building roads, airports and housing at Kenya’s current pace, and Ndugu Transport’s aggregate has gone into regional infrastructure projects for decades.

But the externalities of that work, ground vibration that can propagate through soil and crack masonry, flyrock that becomes lethal when containment fails, dust that affects respiratory health, fall heaviest on residents who live closest to the blast face and have the least power to relocate or litigate.

Many in Mamboleo say they are not opposed to the quarry’s existence, only to operating without the pre-blast structural surveys, real-time vibration monitoring, proper stemming and burden calculations, and community notification protocols that responsible blasting requires.

Residents are now calling on NEMA Director General Mamo Boru Mamo, Environment Cabinet Secretary Deborah Barasa, the State Department for Mining, Governor Nyong’o and the Kisumu County government to fold the Mamboleo quarry into the ongoing audit, order an independent structural and environmental assessment of affected homes, and determine whether compensation is owed where blasting damage can be established.

Ndugu Transport had not issued a public response to the latest allegations at the time of publication.

Given its engineering leadership and its own 2021 pledge to restore and rehabilitate its quarry sites, the company is well positioned to demonstrate, with actual monitoring data rather than reassurance, that blasting at Mamboleo is being conducted to standard. Silence, or another round of unfulfilled commitments, will only deepen a suspicion that is no longer confined to one estate.

This is no longer only a Mamboleo story.

It is a live test of whether Kisumu’s post-Kanyakwar reckoning with its quarry industry reaches operating sites with paying customers and half-century reputations, or whether, as residents fear, well-established firms continue to enjoy a latitude that newer or less connected operators do not.

The audit ordered by the Governor gives regulators the opening. What they do with it, at Mamboleo and everywhere else the ground still shakes, will answer the question residents have been asking for years.