Why We Oppose the Aldi Development on Marsh Lane

1. Poor Design for the Area: The design doesn’t fit the look or feel of the area and puts cars before people and nature.

2. Air and Noise Problems: The site has high air pollution and will add noise near homes and schools, with no strong plan to fix it.

3. More Traffic and Unsafe Roads: The plan will increase traffic, congestion, and road danger, with no real steps to make the area safer.

4. Risk of Crime and Anti-Social Behaviour: Large retail developments can attract late-night activity, loitering, and crime, with no clear safety measures proposed.

5. Pollution Risk: The site is contaminated and could leak pollution into the ground and nearby marsh, with no proper clean-up plan.

6. Loss of Nature and Wildlife: The development causes major loss of wildlife and habitats, with no strong plan to protect or replace them.

7. Cutting Down Mature Trees: Many healthy trees will be cut down or damaged, hurting local greenery and breaking tree protection rules.

8. Harm to Local Shops: No evidence shows the retail won’t harm nearby shops, and the location doesn’t pass the proper retail tests.

9. Too Much Car Parking: The plan includes too many parking spaces and a weak travel plan, which doesn’t support greener transport.

10. No Recycling or Waste Plan: There’s no circular economy plan, so materials and waste won’t be reused or managed well.

11. No Proof of Energy Performance: There’s no plan to track real energy use after building, breaking rules on energy reporting.

12. Weak Public Consultation: Locals were not properly listened to, and there’s no sign their views changed the plan.

This application is in direct conflict with Harrow’s Local Plan, which designates this site (Site O19) for residential development — not retail. It is located outside any designated retail centre, and the applicant has failed the required sequential test under both the London Plan and the NPPF. No compelling evidence has been presented that sequentially preferable, in-centre locations are unavailable.

The application is not only speculative, it risks undermining the integrity of Harrow’s plan-led system. Approval would threaten housing delivery, contradict planning policy, and encourage further unplanned, piecemeal development.

It must also be acknowledged, however, that the site is likely undeliverable for housing due to severe constraints:

• It contains critical underground gas infrastructure, with 24/7 access required by Cadent;

• Large parts of the site fall within easement zones, preventing construction of footings, gardens, or basements;

• The actual developable area is only around 0.43 hectares — less than half the total site — making even modest housing schemes unviable.

Indeed, residential developers have already withdrawn from the site citing these technical barriers. But this does not mean retail is an appropriate fallback. We cannot replace an undeliverable housing site with an unsustainable retail use that would bring daily traffic, noise, and pollution into a quiet residential neighbourhood. The site’s low public transport accessibility (PTAL 1b–2) means most visitors would drive.

Given that neither housing nor retail appears feasible, the Council should consider alternative low-impact uses through a formal Local Plan review. Suitable options could include:

• A local nature recovery area to support biodiversity;

• A community or ecological buffer space;

We therefore urge Harrow Council to reject this application and initiate a transparent, evidence-led reassessment of Site O19’s future, in full consultation with residents.

The proposed Aldi store would duplicate existing food retail in a saturated catchment already served by Sainsbury’s, Lidl, Tesco Express, Morrisons, Iceland, and numerous independent stores. The applicant’s own documents describe Stanmore as a “vital and viable” centre, yet no clear evidence is provided of unmet need.

Aldi’s large, out-of-centre format would draw trade away from Stanmore’s existing supermarket anchors (Sainsbury’s and Lidl), as well as smaller businesses in Whitchurch Lane, Belmont Circle, and Edgware High Street. Industry data shows stores of this size typically result in:

• 15–25% loss for nearby small independents

• 5–15% trade diversion from existing supermarkets

• Decreased footfall across local parades and high streets

This would undermine Stanmore’s town centre role, risking business closures, job losses, and increased vacancies. The applicant also fails both the Sequential Test and Retail Impact Test required under the NPPF, offering no serious assessment of town centre alternatives or local trade impacts.

The proposal breaches planning policy at all levels:

• NPPF  (support centres, assess impact)

• London Plan  (protect local anchors)

• Local policy favouring walkable, small-scale retail
  
  

In short, the scheme meets no proven need, delivers no unique benefit, and risks long-term damage to Stanmore’s retail ecosystem. It should be refused unless fully reassessed.

The proposed Aldi development at Marsh Lane, Stanmore, is expected to generate a substantial increase in both vehicular and pedestrian movements in a highly constrained local road network. Based on figures provided in the applicant’s own Transport Assessment and industry-standard TRICS data, the development will generate:

• Over 1,600 vehicle trips on a typical Saturday, including up to 213 vehicle movements during the Saturday peak hour (12:45–13:45) alone.

• Weekday PM peak hour traffic of 119 vehicle trips, compounding congestion during school pickup and commuter hours.

• Realistically, 10–20% of these trips (160–320 vehicles per day) are “new” trips, not diverted or pass-by journeys as claimed.

• An estimated 150–200 additional pedestrian movements per day directly related to store users and staff.

• Frequent service vehicle activity, including 3–4 HGV deliveries daily, milk and bread deliveries, and 1–2 weekly refuse collections, as well as likely Uber/taxi drop-offs and customer pick-ups, none of which are quantified in traffic projections.

Despite these significant figures, the modelling and assumptions in the Transport Assessment underplay the true impact. For instance, the proposal compares itself with stores in Anerley, Cheam, Romford, and Selsdon, yet:

• The Romford Aldi, in a denser setting with better public transport (PTAL 4–5).

• The Selsdon Aldi shows higher footfall and vehicular turnover, despite smaller store GIA.

• Real-world observations at comparable outer London stores indicate sustained Saturday volumes of 1,800–2,200 daily vehicles, exceeding the conservative trip forecasts presented here.

The proposed Aldi store at Marsh Lane raises serious concerns about increased crime and antisocial behaviour in a currently low-crime, residential area.

The layout includes a rear access route via Wychwood Avenue and open boundaries to Stanmore Marsh, creating unmonitored escape routes and gateways into quiet neighbourhoods. These are known risk factors for burglary, loitering, drug activity, and youth disorder, especially in areas with limited police presence.

Evidence shows developments with high footfall and poor boundary security can raise local crime by up to 35% within 500m. The site’s lack of CCTV, security staff or evening surveillance heightens this risk, especially given Aldi’s low-intervention operating model.

There is also concern about violent incidents, with rising reports of staff assaults and disputes at similar discount stores. The proposal makes no provision for conflict prevention or emergency response, putting staff and customers at risk.

Children and elderly residents are particularly vulnerable. The site lies within walking distance of local schools, with new footpaths likely to become unsupervised routes. Older people may be deterred from using public space if antisocial behaviour increases.

Despite these risks, the application offers no crime prevention strategy, violating key safety standards under London Plan and NPPF. Without redesign and meaningful security measures, the proposal presents a public safety hazard and should be refused on these grounds.

The proposed development sits on a heavily contaminated former gasworks site, with confirmed high levels of ammonium (up to 100,000 µg/L), PAHs, cyanide, and hydrocarbons in soil and groundwater. The site overlies a Secondary A aquifer within permeable alluvium, putting sensitive groundwater and nearby receptors such as Stanmore Marsh and Edgware Brook (River Brent catchment) at direct risk. Evidence shows ongoing lateral and vertical migration of pollutants.

Despite these risks, large areas beneath hardstanding remain uninvestigated, and no borehole monitoring has been carried out in downgradient locations. The Environment Agency has not approved any remediation plan.

Alarmingly, the applicant proposes a “do nothing” remediation strategy—chosen for cost reasons—despite its failure to meet environmental safety standards. This approach breaches the Water Framework Directive, Environmental Permitting Regulations 2016, Environmental Damage Regulations 2015, and contradicts NPPF and Land Contamination Risk Management (LCRM) guidance, which require full investigation and mitigation before development.

Without thorough remediation and regulatory approval, the application poses a serious threat to public health, water quality, and environmental safety, and should be refused.

The site is located in an area identified by the Environment Agency as medium to high risk for surface water flooding, with expected flood depths of up to 0.6m in a 1-in-30-year event. However, the applicant’s Flood Risk Assessment (FRA) underestimates both current and future risk, and the drainage strategy lacks essential safeguards.

The proposed Sustainable Drainage System (SuDS) channels runoff directly into Stanmore Marsh, a protected SINC, without proper treatment. No hydrocarbon filters, sediment traps, or pollution controls are included, and there is no long-term maintenance plan or adoption agreement in place.

The scheme also uses a rainfall intensity uplift of just 20–25% for climate change, despite guidance recommending 40% or more, increasing the risk of downstream flooding and pollution.

This strategy fails to comply with:

• NPPF (requirement to avoid and mitigate flood risk)

• London Plan Policy (SuDS must protect water quality and biodiversity)

As currently proposed, the development exports flood and pollution risk into a sensitive ecological area, and should be refused.

The proposed development will cause serious ecological harm, both on-site and to the nearby Stanmore Marsh Site of Importance for Nature Conservation (SINC), located just 350 metres away. The marsh supports protected species, including common toads, hedgehogs, butterflies, and Section 41 plants, and plays a key role in flood control and biodiversity.

The application results in a 29.42% net loss in habitat units, directly breaching the Environment Act 2021, which requires a minimum 10% biodiversity net gain. No off-site compensation, biodiversity credits, or Section 106 agreement have been proposed to address this shortfall.

Additionally, the scheme removes valuable scrub and grassland habitats and creates edge effects such as light pollution, trampling, and runoff. Increased hard surfacing raises the risk of polluted water entering Edgware Brook, threatening water quality, habitats, and downstream ecosystems.

This proposal conflicts with:

• NPPF (protect biodiversity and ecological networks)

• London Plan Policy (safeguard SINCs and manage water impacts)

• Harrow Core Strategy 

Without secured biodiversity mitigation and ecological safeguards, this application risks long-term, irreversible environmental damage and should be refused.

The proposal involves the unjustified removal of two mature oak trees (T8 and T9) and threatens the health of several others due to excessive root zone intrusion. The Tree Protection Plan and Arboricultural Method Statement were not finalised before submission, with key information on no-dig surfacing and root protection deferred to post-approval — contrary to best practice.

Root Protection Areas (RPAs) of retained trees (T4, T7, G13, G15) would be intruded upon by 22–33%, breaching BS5837:2012 guidance. These trees are ecologically important and contribute significantly to local character, wildlife habitat, and residential amenity. Their loss or decline would result in permanent environmental harm.

Additionally, the site achieves an Urban Greening Factor (UGF) of just 0.252, falling short of the London Plan minimum of 0.3 for commercial developments. No meaningful redesign of the building or car park layout has been proposed to reduce this deficit.

This application fails to meet minimum standards for tree protection and urban greening, and should not be approved in its current form.

The site lies within an Air Quality Management Area (AQMA), where pollution levels for PM2.5 and NO₂ already exceed safe limits. Despite this, the submitted Air Quality Assessment omits worst-case modelling and fails to assess cumulative impacts—particularly during school hours when traffic and exposure peak.

The proposal includes no mitigation measures, such as:

• Electrified delivery vehicles

• Anti-idling enforcement

• Buffer planting near homes and schools

• Traffic calming or modal shift strategies

It does not achieve “Air Quality Neutral” compliance, failing both in measurable benchmarks and in mitigation planning.

In terms of noise, the store proposes 7-day operation from 7am to 10pm, with deliveries starting as early as 6am. The Noise Impact Assessment overlooks key sources like reverse alarms and unloading, and does not account for facade reflections. Nearby homes on Wychwood Avenue, Marsh Lane, and Wildcroft Gardens will be impacted by chronic noise and light pollution, resulting in substantial amenity loss.

This application fails to safeguard public health or residential quality of life, and should be refused unless fully redesigned.

The proposed development is within walking distance of Whitchurch Primary, Honeypot Pre-School, and Avanti House School, placing hundreds of children in direct proximity to a site associated with traffic, pollution, and contamination risks. Despite this, the application provides no health impact assessment for child exposure.

Children are especially vulnerable to air pollution (PM2.5, NO₂), which is linked to asthma, impaired lung development, and cognitive harm, particularly in ethnic minority and lower-income populations — groups well represented in this area.

Noise from early deliveries, reverse alarms, and site activity also poses risks to children’s sleep and concentration, as recognised by the World Health Organization. These effects can be long-term and developmental.

Additionally, the site contains untreated contamination, including ammonium and hydrocarbons, posing latent health risks to children who live nearby or use local parks.

The proposal breaches:

• NPPF (protecting public health)

• London Plan (safeguarding vulnerable groups)

• UN Convention on the Rights of the Child, Article 24 (right to a healthy environment)

Without robust health safeguards, the scheme endangers local children and should be refused.

The proposed development fails key sustainability requirements set by the London Plan and Harrow’s environmental goals. It includes no Circular Economy Statement (in breach of Policy SI7), offers only basic Part L energy compliance, and lacks any commitment to “Be Seen” post-occupancy carbon monitoring (required under SI2).

There is no local renewable energy generation or storage, and no nature-based features such as green roofs, rainwater harvesting, or climate-resilient landscaping. The scheme includes a vast impermeable footprint, worsening surface runoff and reducing urban cooling potential.

Combined with a 29.4% biodiversity net loss and a substandard Urban Greening Factor (UGF) of 0.252, the proposal is carbon-intensive, resource-inefficient, and falls well short of London’s target to become a zero-carbon city.

This application does not meet minimum sustainability expectations and should be refused unless radically improved.

The consultation process falls short of the requirements in Harrow Council’s Statement of Community Involvement (SCI) and the National Planning Policy Framework (NPPF).

The associated Aldi Feedback Report reveals significant flaws:

• No location data for respondents—proximity is critical in planning, especially for developments affecting traffic and residential amenity.

• Biased survey design, with emotive and leading language, and no neutral questions allowing objections or alternatives.

• Overstated support: Aldi claims 61% in favour, yet more than 1,000 residents have signed a petition against the scheme and 95% of formal comments on Harrow’s portal, to date, are objections.

• No demographic data or cross-tabulation by distance or impact.

• Privately run and unverified, the survey does not meet the standards of a robust or objective consultation.

Aldi’s process offered a single, fixed proposal with no evidence that resident feedback influenced any revisions. There were no alternative layouts, access routes, or parking configurations presented. Key local stakeholders—including councillors, schools, biodiversity officers, and environmental groups—were not meaningfully involved. Despite receiving over 250 objections, the applicant issued no formal response.

This consultation lacks the transparency, inclusivity, and responsiveness required by Harrow’s SCI and the NPPF. It cannot be considered a meaningful reflection of community views.

We respectfully urge Harrow planning officiers to disregard Aldi’s internal survey and instead consider the overwhelming public opposition.