Water Services. Revenue increased $110.1 million, or 25.7%, to $539.3 million for the Current Period compared to $429.1 million for the Prior Period. The increase was primarily attributable to incremental revenue contributions from the Breakwater Acquisition and higher demand for our services coupled with increased pricing in comparison to the Prior Quarter. The increase in demand was due to market activity increases across most of our areas of operations, market share gains in the Permian Basin in our poly and containment business line and new service offerings in our accommodations and rentals business line.
Water Infrastructure. Revenue increased by $61.4 million, or 124.5%, to $110.7 million for the Current Period compared to $49.3 million for the Prior Period. The increase was primarily attributable to higher demand for our services in comparison to the Prior Period, as well as by incremental revenue contributed by the Nuverra, Breakwater, Cypress and other asset acquisitions. Revenue during the Current Period also benefitted by the commencement of operations associated with a long-term agreement recently signed for water pipeline distribution in the Rockies region.
Chemical Technologies. Revenue increased $19.0 million, or 12.5%, to $171.2 million for the Current Period compared to $152.2 million for the Prior Period. The increase was primarily attributable to higher demand for our services in comparison to the Prior Period and was not directly impacted by acquisition activity.
Costs of Revenue
Costs of revenue increased $130.1 million, or 22.8%, to $700.4 million for the Current Period compared to $570.3 million for the Prior Period. The increase was primarily composed of a $73.1 million increase in Water Services costs, a $37.7 million increase in Water Infrastructure costs, and a $6.9 million increase in Chemical Technologies costs due to supporting the higher revenue-producing activity discussed above.
Water Services. Costs of revenue increased $73.1 million, or 20.7%, to $426.5 million for the Current Period compared to $353.4 million for the Prior Period. Cost of revenue as a percent of revenue decreased from 82.4% to 79.1% due primarily to higher pricing for our services and economies of scale from higher revenue activity.
Water Infrastructure. Costs of revenue increased $37.7 million, or 121.5%, to $68.7 million for the Current Period compared to $31.0 million for the Prior Period. Cost of revenue as a percent of revenue decreased from 62.9% to 62.1% due primarily increased water treatment and recycling margins, which were favorably impacted by the Breakwater Acquisition.
Chemical Technologies. Costs of revenue increased $6.9 million, or 5.3%, to $137.0 million for the Current Period compared to $130.2 million for the Prior Period. Cost of revenue as a percent of revenue decreased from 85.5% to 80.0% due primarily to picking up additional higher-margin market share within our portfolio of products as well as manufacturing process efficiencies.
Depreciation and Amortization. Depreciation and amortization expense increased $12.4 million, or 22.2%, to $68.1 million for the Current Period compared to $55.8 million for the Prior Period, due primarily to a higher fixed asset base and six full months of depreciation related to the Breakwater, Cypress, and Nuverra Acquisitions.
Gross Profit
Gross profit was $120.8 million for the Current Period compared to $60.3 million for the Prior Period due primarily to higher revenue in all three segments resulting from increased activity levels and pricing and contributions from the Breakwater and Cypress Acquisitions. Gross profit increased by $37.0 million, $23.7 million and $12.1 million in our Water Services, Water Infrastructure and Chemical Technologies segments, respectively. Partially offsetting the increase in gross profit was a $12.4 million increase in depreciation and amortization expense. Gross margin as a percent of revenue was 14.7% and 9.6% in the Current Period and Prior Period, respectively.
Selling, General and Administrative Expenses
Selling, general and administrative expenses increased $15.2 million, or 27.5%, to $70.2 million for the Current Period compared to $55.0 million for the Prior Period. The increase was due primarily to $4.3 million higher wages,