North Carolina Stormwater Compliance Evaluation for the 20 Coastal Counties

Stormwater is one of the largest sources of pollutants in the United States and contributes sediment, heavy metals, oil, pesticides, fertilizers, bacteria, and other contaminants to coastal waters. Water quality is critical to coastal areas for commercial fishery health and recreational activities. To minimize the introduction of water quality pollutants, North Carolina implemented the State Stormwater Program (SSP) for post construction stormwater management. A study in 2005 identified low compliance rates with the SSP (30.7%) and a follow-up in 2009 found that only 20% of noncompliant sites had rectified their violations. There are currently no studies documenting recent compliance rates with the SSP. This study addressed three objectives: (1) Update the compliance study to include recent trends in compliance and reasons for violations (2) Determine the perceptions of the strengths and opportunities for improvement, and (3) Conduct a program analysis of the SSP. These objectives were achieved by analyzing compliance data from the Division of Energy, Mineral, and Land Resources, conducting interviews with a small sample of entities that interact with the SSP, and reviewing applicable compliance literature. The results of our study show potential areas for improvement and were used to make policy recommendations for North Carolina to increase compliance with these regulations. Our results indicate that compared to the 2005 estimate, compliance in 2012 increased to 50%, and was lower in coastal counties than noncoastal counties. In total there were 2,838 compliance inspections between 2008 and 2012. Yearly inspections increased between 2008 and 2010, but decreased sharply in 2011 and remained low in 2012. The majority of violations were due to reporting and maintenance issues. Interview respondents indicated that the main impediments to compliance are maintenance and education, and that compliance could be improved through increased maintenance checks and public outreach efforts. The program analysis showed that while the stormwater program generally has clear regulations, it could benefit from increased visibility of the regulating agency, engagement, as well as education. Potential avenues for improvement are discussed, and are considered within the context of our findings

Search for dark matter produced in association with bottom or top quarks in √s = 13 TeV pp collisions with the ATLAS detector

A search for weakly interacting massive particle dark matter produced in association with bottom or top quarks is presented. Final states containing third-generation quarks and miss- ing transverse momentum are considered. The analysis uses 36.1 fb−1 of proton–proton collision data recorded by the ATLAS experiment at √s = 13 TeV in 2015 and 2016. No significant excess of events above the estimated backgrounds is observed. The results are in- terpreted in the framework of simplified models of spin-0 dark-matter mediators. For colour- neutral spin-0 mediators produced in association with top quarks and decaying into a pair of dark-matter particles, mediator masses below 50 GeV are excluded assuming a dark-matter candidate mass of 1 GeV and unitary couplings. For scalar and pseudoscalar mediators produced in association with bottom quarks, the search sets limits on the production cross- section of 300 times the predicted rate for mediators with masses between 10 and 50 GeV and assuming a dark-matter mass of 1 GeV and unitary coupling. Constraints on colour- charged scalar simplified models are also presented. Assuming a dark-matter particle mass of 35 GeV, mediator particles with mass below 1.1 TeV are excluded for couplings yielding a dark-matter relic density consistent with measurements