[This dataset is embargoed until August 31, 2026]. This dataset includes measurements of groundwater levels, salinity, and pH collected from 36 dug wells, along with rainfall data, on the Indian Ocean island of Karainagar, Sri Lanka, spanning the period from 2019 to 2024. Karainagar, the study area, is one of seven islands located off the coast of Jaffna in northern Sri Lanka. This rectangular island is bounded on three sides by the Palk Strait, while the fourth side faces the Jaffna Lagoon and is connected to the mainland by a causeway. Karainagar covers an area of approximately 22 km², including inland water bodies. Thirty-six dug wells—used for agricultural, domestic, Kovil (Temple), and public purposes—were inventoried. These wells were monitored to track groundwater levels and key physicochemical parameters, specifically salinity (measured as electrical conductivity, EC) and pH, on Karainagar Island. Full details about this dataset can be found at https://doi.org/10.5285/ba22d53b-4eee-48a1-b6f3-653d252c0358

This dataset contains nitrogen data from nitrate, ammonium and nitrite, total nitrogen and carbon data, and elemental composition data from anaerobic digestate and biomass ash from UK bioenergy production. Anaerobic digestate was sampled 8 times from different industrial scale plants across the UK between January 2015 and January 2018 and biomass ash was sampled in January 2015 and June 2016. Anaerobic digestate was sourced from segregated food waste (mainly household waste), pig slurry, maize silage, vegetables waste, sweet corn waste, aerobically treated food waste, food manufacturer waste and other biodegradable sludge from within the UK. Biomass ash, both fly and bottom ash, from virgin and recycled wood was sourced from three sites within the UK and one from Spain. All laboratory analyses were undertaken at Lancaster University using standardised methods. The data were collected as part of the research grant, Developing a suite of novel land conditioners and plant fertilizers from the waste streams of biomass energy generation. The research was funded by NERC, award NE/L014122/1. Full details about this dataset can be found at https://doi.org/10.5285/990c54f6-5c92-4054-8bfa-953533a89149