As you can see on Slide 4, total sales for the second quarter were $122.9 million compared to the coronavirus impacted trough of $91.1 million in the same period last year, an increase of 35%.
Overall utility water sales increased 38%.
Excluding the approximately $12 million of sales from s::can and ATi acquisitions, core utility water revenues increased 22% year-over-year.
Comparing back to the pre-COVID impacted second quarter of 2019, core utility water sales increased 11%.
As anticipated, the flow instrumentation product line sales rate of change returned to growth with a 22% year-over-year improvement, stabilizing demand trends across the majority of global end markets and applications as well as an easier comp influenced the increase.
The quarter's operating margin was 15.2%, an increase of 130 basis points year-over-year.
Gross margin for the quarter was 40.8%, an increase of 150 basis points year-over-year.
Taking a closer look at copper, prices have settled back down into the $4.30 range after escalating to about $4.80 earlier in the quarter.
This is generally in line with our most recent year-over-year headwind estimate, which was approximately $7 million to $8 million on a full year basis unmitigated.
The second quarter spend of $31.4 million was sequentially in line with the $31.6 million from Q1 2021 and represents an increase of $8.2 million from the prior year.
The SEA run rate includes both the s::can and ATi along with the higher level of acquired intangible asset amortization, and is in line with our ongoing expectations of normalized SEA leverage in 25% to 26% range over time.
The income tax provision in the second quarter of 2021 was 25%, slightly higher than the prior year's 24.3% rate.
In summary, earnings per share was $0.48 in the second quarter of 2021, an increase of 45% from the prior year's earnings per share of $0.33.
Working capital as a percent of sales was 24.3% on par with the prior quarter-end.
Free cash flow of $11.9 million was lower than the prior year, the result of higher cash tax payments and the increase in inventory.
On a year-to-date basis, free cash flow conversion of net earnings is sitting at 147%.
We took the opportunity to upsize the facility to $150 million and to add additional flexibility in the form of leverage covenants and an accordion feature among others.
We are very pleased with the results from the last two water quality acquisitions this quarter contributing just over $12 million of revenue in the quarter, a pro forma growth rate in the double-digits.
One is an outline of how Badger Meter works to align our ESG efforts with the United Nations Sustainable Development Goals, notably Goal 6, 3 and 11 that focus on water, health and safety and sustainable cities.

Summary:
As you can see on Slide 4, total sales for the second quarter were $122.9 million compared to the coronavirus impacted trough of $91.1 million in the same period last year, an increase of 35%.
In summary, earnings per share was $0.48 in the second quarter of 2021, an increase of 45% from the prior year's earnings per share of $0.33.