Agenda item

Bath Clean Air Plan- update December 2021

To achieve compliance with Ministerial Directions, on 15 March 2021 a Clean Air Zone (CAZ) was launched in Bath, the first charging CAZ outside of London.

Whilst many of the monitoring measures, including air quality, are ordinarily reported on an annual basis, this report is the second in a series which provides an indicative view of the performance of the Clean Air Zone in Bath from July-September 2021.


Councillor Sarah Warren introduced the report and made the following statement:


“Air pollution is estimated to cause around 80 deaths a day across the UK, with approximately 80 per year in Bath and North East Somerset. The World Health Organisation recently released new guidelines on safe levels of 6 pollutants where evidence has advanced on the health effects from exposure, and I have written this week to the Minister to urge their rapid adoption into UK law, combined with adequate advice, powers and financial support for councils in tackling them, so as to reduce these adverse health impacts.

Tonight we are considering the second quarterly report on air quality, vehicle compliance, and traffic displacement following the implementation in March 2021 of Bath’s Clean Air Zone, which is designed to tackle high atmospheric levels of the pollutant nitrogen dioxide. The report covers the period from July to September of this year.

Nitrogen dioxide levels are usually measured and compared over 12 month average periods because of the way its concentration in the atmosphere fluctuates depending on seasonal weather conditions. Therefore this report on just 3 months from July to September, covers a very short period by these standards, and presents provisional data, not yet subject to bias corrections or validation.

During the quarter we saw overall traffic levels return to pre-covid levels in the city, with light goods vehicles at 112% and heavy goods vehicles at 110% of their pre-covid numbers, owing to pandemic-related changes in shopping patterns. Throughout the period, there have been dramatic changes to traffic flows around the city centre arising from the complete closure of Cleveland Bridge, which normally carries some 17,000 vehicles per day.

The purpose of the zone is to encourage the upgrade of the most polluting vehicles, and £9.4m has been made available through grants and interest free finance to support this. Some 1495 individuals have been approved for finance, and 591 vehicles upgraded so far through this route, with others delayed due to issues with global supply of new vehicles. Overall, air quality continues to improve both within and outside the zone, with average reductions in nitrogen dioxide levels 14% inside, and 9% outside the zone, compared to the same period in 2019.


·  91% of all taxis, 96% of HGVs, and almost 100% of scheduled bus services driving in the zone are compliant.

·  We’ve seen an increase to 77% of compliant light goods vehicles travelling in the zone.

·  Of the 40,000 vehicles entering the zone each day, non-compliant vehicles are down to just 1.7%.

·  The income generated between March and the end of September totalled around £3.5m, all of which will go into reserve funds to pay for the future operation of the scheme in the interests of public health.

I particularly want to thank those people who have gone to the trouble and expense of upgrading their vehicles, whether independently or through the council scheme, as well as those who are still on waiting lists for new vehicles, because we are seeing the benefits of the high level of vehicle compliance. I received an email from the wife of an asthmatic only this week expressing heartfelt thanks for the efforts we have all made as a community to reduce air pollution.

Bearing in mind that we have to take a 12 month view of pollution, we are still seeing nine sites with average nitrogen dioxide levels above 40 microgrammes per cubic metre over the quarter. Four of these locations have seen a decrease in emissions compared to the same period in 2019, which is pleasing. However, four have seen an increase, and they are probably all impacted to a greater or lesser extent by diversions arising from the Cleveland Bridge closure. Further detailed investigations are continuing at these locations, however, to ensure we fully understand what is going on.

In particular, I note that a recent newspaper article cites Chapel Row as the most polluted street in Bath, without expanding on the reasons behind the temporary rise in pollution seen here. From the closure of Cleveland Bridge in late June, we saw an increase in traffic flow northwards into Queen Square from 5,300 vehicles to 6,500 per week.

Graphs in our report show an exact correlation between this rise in traffic on Chapel Row and the rise in nitrogen dioxide concentrations at the corresponding diffusion tubes. I’d therefore like to reassure residents and businesses in the area that we fully expect nitrogen dioxide levels at Chapel Row to fall back below 40 micrograms per cubic metre now that the bridge has reopened. This was a temporary increase, due to the closure of the bridge.

Whilst the overall reduction in pollution we have seen across the city is positive, it is somewhat disappointing to note that despite largescale displacement of HGVs away from Cleveland Place during the bridge closure, pollution levels at Walcot Parade remain above 40 microgrammes per cubic metre, and there are a couple of other pollution hotspots where I would prefer to be seeing a faster reduction in pollutant levels.

There are also a number of areas around the city where we are seeing some displacement of traffic, and with Cleveland Bridge closed, it is often hard to determine whether this is due to the Clean Air Zone, to the bridge closure, or to the overall national increase in heavy and light goods vehicles on our roads since the pandemic. Only longer term and more detailed monitoring, particularly following the reopening of the bridge, will enable us to tease out these different elements.

The data collected during the bridge closure to date does show us clearly that removing many vehicles from this part of the network has seen a dramatic reduction in air pollution, and the next quarterly monitoring report will show us exactly what air quality at Cleveland Place is like with cars and without trucks, as the bridge is currently closed to vehicles wider than 2m. This information is relevant to the next item on this evening’s agenda, which recommends use of an amended Clean Air Zone charging order to charge all diesel HGVs above 12 tonnes to enter the zone unless exempt. I would like to register my concern that if large vehicles are allowed to return to the bridge, we can expect a return of pollution to Cleveland Place.

I would like to finish by thanking officers for their hard work monitoring the impacts of the zone so closely, and compiling the data into this quarterly report, which permits regular close public examination of our progress on this important public health measure. We clearly need to keep both air quality and potential traffic displacement under close review. We await government’s assessment of the extent to which we are achieving success in the New Year.

In the meantime, given that our legal compliance with air quality standards now looks as though it may be marginal at a small number of locations in the city, I would like to amend the final recommendation (in the report), to additionally request an options appraisal for making further improvements to air quality in the city, as part of our next published report about the Clean Air Zone”.


Councillor Sarah Warren moved the recommendations, as amended.


Councillor Dine Romero seconded the motion and stated that a key factor behind the Clean Air Zone is the public health implications of bad air quality. She stated that climate change and public health are good reasons to support The Clean Air Zone but acknowledged variables such as the work on Cleveland Bridge.


Councillor Richard Samuel made the following statement: “Once again, I welcome the publication of this report which places the facts concerning the CAZ in the public domain and represents the official state of play rather than some of the ill-informed comments I have seen on social media from certain members of the main opposition party.

Overall, I am pleased to see a trend towards reduction of pollutants, but I am concerned to see that pollution levels remain above legal levels in my ward and also in a number of city centre sites.

I want to speak briefly on one of these – Chapel Row.

When the last administration’s then cabinet member, Cllr Goodman, proposed the traffic light scheme at Queen Square, he set in train the sequence of events that have led to the higher pollution levels we see today. In 2019 the Conservative administration were so desperate to avoid charging cars to come into the CAZ, a Class D CAZ, that came up with this bonkers scheme.

 One of the areas where pollution was above legal limits was the corner of Gay St and George St which is a notorious pinch point. The other was at Cleveland Place in my ward.

Failure to achieve compliance at these pinch points would have meant that air quality would always have failed the standard and therefore the council would have to impose a Class D CAZ. So, Cllr Goodman came up with the Heath Robinson solution we see today. Two sets of traffic lights installed at Queen Square which are designed to hold traffic back when pollution tips over the limit at Gay St. However, he offered no solution to the Cleveland Place pollution levels.

The inevitable consequence of this plan, which I criticised at the time, was queuing traffic in Chapel Row and around Queen Sq.

Once in power Cllr Warren and I looked extremely closely at the scheme because we did not like it and felt it would displace traffic into lower Lansdown. We asked officers to produce modelling to demonstrate what would happen if the scheme was scrapped. The data they provided showed huge increases in Marlborough Lane, Julian Road, and Royal Avenue to unacceptable levels. This was a deliberate attempt by the Conservatives to disperse pollution into residential areas to reduce it at the pinch-point.

In short it was a deliberate attempt to massage the figures down to achieve a Class C CAZ when all the data showed that a Class D CAZ was probably the correct course of action for the Conservatives to have taken following the science. It also meant that the projections for Gay St and Cleveland Place were within a 3% margin of error and so statistically unreliable as a certain outcome.

Despite our best endeavours it proved impossible to unpick this decision, despite the now Mr Goodman’s claims to the contrary, as this would have meant missing the deadlines set by JAQU and additional cost to remodel the CAZ.

The result is clear to see.

I also note the downgrading of aspiration by the Tory government from compliance to achieving success. Weasel words if ever I heard them.

But I also want to reflect on the diversionary impacts that are clearly occurring and are referred to in para 3.7 of the report. Whilst these are perhaps explainable they are not desirable. I therefore call on my colleague Cllr Warren to agree to examine these negative impacts and if justified bring forward amendments to the charging order that discourage commercial vehicles from impacting on residential areas. I raise this now as there is a clear connection to the recommendations contained in the next report.

Finally, I want to end by commenting on the NOx figures for the monitoring sites in my ward.

·  Anglo Terrace – dramatically down because of the HGV ban

·  Paragon – up because of diverting vehicles

·  Walcot Parade – down because of the HGV ban

·  Canton Place – down because of the HGV ban

·  Walcot St – marginally down

·  Cleveland Place- down because of the HGV ban.

Chairman if ever an evidence base was required for a permanent restriction on all HGVs over Cleveland Bridge this was it”.



RESOLVED (unanimously) to recommendthat the Cabinet on 16th December 2021:


1.1  Note the performance report and the ongoing progress which has been made towards improving air quality and associated public health outcomes, together with the ongoing increasing proportion of compliant vehicles entering the CAZ and achieving success with the Ministerial Direction.

1.2  Note the continued performance of the scheme against the scheme’s financial model, ensuring it covers its costs of operation and avoids placing an additional burden on the Council and local taxpayers.

1.3  Note that after assessing over 2,500 applicants who applied to the financial assistance scheme and finding 1,495 vehicles eligible for replacement or retrofit treatment, the current round of funding for the financial assistance scheme will be concluding. However, a waiting list is being held, should further funding become available.

1.4  Note the success achieved at key hotspot monitoring locations in reducing nitrogen dioxide levels e.g. Gay Street, acknowledge the risk that more intervention may be required at some locations, e.g. Wells Road and note the work that Officers have already been doing in anticipation of this outcome.

1.5  Request an options appraisal for making further improvements to air quality in the city, as part of our next published report about the Clean Air Zone.


Supporting documents: