16. Income Taxes

The following table presents the provision for income taxes for the respective periods:

	Three Months Ended September 30,						Nine Months Ended September 30,
(dollars in thousands)	2018			2017			2018			2017
Provision for income taxes	$	8,692		$	21,249		$	7,357		$	16,841
Effective tax rate		12.8	%		30.7	%		14.5	%		29.4	%

Our effective tax rate for the three and nine months ended September 30, 2018 decreased to 12.8% from 30.7% and to 14.5% from 29.4%, respectively, when compared to the same periods in 2017. This change was primarily due to Tax Reform enacted in December 2017 and adjustments to provisional amounts, discussed below, which is partially offset by one-time nondeductible acquisition and integration expenses.

On December 22, 2017, Tax Reform was signed into law. As a result of Tax Reform, the U.S. statutory tax rate was lowered from 35% to 21% effective January 1, 2018, a territorial tax system was implemented, and a one-time repatriation tax on deemed repatriated earnings of foreign subsidiaries was imposed, among other changes. ASC Topic 740, Accounting for Income Taxes, requires companies to recognize the effect of tax law changes in the period of enactment. ASU 2018-05, Income Taxes (Topic 740) - Amendments to SEC Paragraphs Pursuant to SEC Staff Accounting Bulletin No.118, allows a company to record a provisional amount when it does not have the necessary information available, prepared, or analyzed (including computations) in reasonable detail to complete the accounting for certain tax effects of Tax Reform. The Company has recognized the provisional tax impacts of Tax Reform in its consolidated financial statements as of September 30, 2018. On June 14, 2018, the Company acquired Layne recognizing provisional tax impacts of Tax Reform in the opening balance sheet including assessing our intent to indefinitely reinvest certain earnings of our foreign subsidiaries and affiliates. The majority of the provisional tax impacts of Tax Reform recorded in the Company’s condensed consolidated financial statements as of September 30, 2018 are related to the revaluation of deferred tax assets and liabilities and the one-time repatriation tax. In the third quarter of 2018, a $7.6 million benefit to the provisional amounts was recorded for the revaluation of deferred tax assets and liabilities including adjustments to two unconsolidated joint ventures based on changes to the tax positions taken by the related consolidating joint venture partners during the third quarter. We continue to assess new guidance and refine our computation of the provisional tax impacts discussed above and will complete our analysis within the one-year measurement period ending December 22, 2018.

An uncertain tax position liability was assumed as part of the Layne acquisition on June 14, 2018 of which $13.1 million is included in other long-term liabilities in the Company’s condensed consolidated balance sheet as of September 30, 2018.