diff --git a/DESCRIPTION b/DESCRIPTION
index 916c69e..57ac985 100644
--- a/DESCRIPTION
+++ b/DESCRIPTION
@@ -1,6 +1,6 @@
 Package: compasstools
 Title: COMPASS Utilities and Tools
-Version: 0.2
+Version: 2.1
 Authors@R: c(
     person("Ben", "Bond-Lamberty", email = "bondlamberty@pnnl.gov",
         role = c("aut", "cre"), comment = c(ORCID = "0000-0001-9525-4633")),
@@ -19,7 +19,8 @@ Imports:
     fpeek,
     lubridate,
     tidyr (>= 1.0),
-    dplyr (>= 1.0)
+    dplyr (>= 1.0),
+    arrow (>= 20.0)
 Suggests: 
     rdrop2 (>= 0.8),
     covr,
diff --git a/NAMESPACE b/NAMESPACE
index b92c55f..6f3f00b 100644
--- a/NAMESPACE
+++ b/NAMESPACE
@@ -5,6 +5,8 @@ export(nearest_neighbor_TMP)
 export(process_aquatroll_dir)
 export(process_sapflow_dir)
 export(process_teros_dir)
+export(read_L1_variable)
+export(read_L2_variable)
 export(read_aquatroll200_file)
 export(read_aquatroll600_file)
 export(read_datalogger_file)
@@ -14,6 +16,7 @@ export(read_teros_file)
 export(scan_folders)
 import(dplyr)
 import(fpeek)
+importFrom(arrow,read_parquet)
 importFrom(dplyr,bind_rows)
 importFrom(lubridate,ymd_hms)
 importFrom(readr,col_character)
diff --git a/R/read_Lx_variable.R b/R/read_Lx_variable.R
new file mode 100644
index 0000000..41c789b
--- /dev/null
+++ b/R/read_Lx_variable.R
@@ -0,0 +1,106 @@
+# read_Lx_variable.R
+
+# These two functions share 95% of their code, but they're short
+
+
+#' Read L1 (Level 1) sensor data files
+#'
+#' This function reads the COMPASS-FME L1 data files (CSV format)
+#' for a single variable, from one or more sites, and returns
+#' the compiled data.
+#'
+#' @param variable Variable name ('research name') to be read, character
+#' @param path Path of the L1 dataset, character
+#' @param site Optional name of the site(s) of data to read, character
+#' @param quiet Print diagnostic information? Logical
+#' @importFrom dplyr bind_rows
+#' @importFrom readr read_csv
+#' @returns A \code{\link[tibble]{tibble}} of L1 data.
+#' @export
+#' @author BBL
+#' @note This function only works for L1 v2-0 (July 2025) and higher.
+#' @examples
+#' \dontrun{
+#' read_L1_variable("gw-tds", site = "TMP")
+#' read_L1_variable("gw-tds", c("TMP", "OWC")) # multiple sites
+#' read_L1_variable(variable = "gw-tds") # will read all sites' data
+#' read_L1_variable(variable = "gw-tds", path = "/path/to/L1/data")
+#' }
+read_L1_variable <- function(variable, path, site = NULL, quiet = FALSE) {
+
+    if(length(variable) > 1) {
+        stop("Only one variable can be read at a time")
+    }
+    if(is.null(site)) {
+        sites <- "[A-Z]*"
+    } else {
+        sites <- paste0("(", paste(site, collapse = "|"), ")")
+    }
+    # Construct regular expression to identify files
+    regex <- paste0("^", sites, "_[A-Z0-9]+_.*_", variable, "_L1_.*csv$")
+    if(!quiet) message(regex)
+    files <- list.files(path, pattern = regex, recursive = TRUE)
+    if(!quiet) message("Reading ", length(files), " files")
+
+    # The function works fine reading zero files, but this is
+    # probably not what the user wants
+    if(length(files) == 0) warning("No files found")
+
+    x <- lapply(files, function(f) {
+        if(!quiet) message("\t", f)
+        read_csv(file.path(path, f), col_types = "ccTccccdcclll")
+    })
+    bind_rows(x)
+}
+
+
+
+#' Read L2 (Level 2) sensor data files (Parquet format)
+#'
+#' This function reads the COMPASS-FME L2 data files (Parquet format)
+#' for a single variable, from one or more sites, and returns
+#' the compiled data.
+#'
+#' @param variable Variable name ('research name') to be read, character
+#' @param path Path of the L2 dataset, character
+#' @param site Optional name of the site(s) of data to read, character
+#' @param quiet Print diagnostic information? Logical
+#' @importFrom dplyr bind_rows
+#' @importFrom arrow read_parquet
+#' @returns A \code{\link[tibble]{tibble}} of L2 data.
+#' @export
+#' @author BBL
+#' @note This function only works for L2 v2-0 (July 2025) and higher.
+#' @examples
+#' \dontrun{
+#' read_L2_variable("gw-tds", site = "TMP")
+#' read_L2_variable("gw-tds", c("TMP", "OWC")) # multiple sites
+#' read_L2_variable(variable = "gw-tds") # will read all sites' data
+#' read_L2_variable(variable = "gw-tds", path = "/path/to/L2/data")
+#' }
+read_L2_variable <- function(variable, path, site = NULL, quiet = FALSE) {
+
+    if(length(variable) > 1) {
+        stop("Only one variable can be read at a time")
+    }
+    if(is.null(site)) {
+        sites <- "[A-Z]*"
+    } else {
+        sites <- paste0("(", paste(site, collapse = "|"), ")")
+    }
+    # Construct regular expression to identify files
+    regex <- paste0("^", sites, "_[A-Z0-9]+_.*_", variable, "_L2_.*parquet$")
+    if(!quiet) message(regex)
+    files <- list.files(path, pattern = regex, recursive = TRUE)
+    if(!quiet) message("Reading ", length(files), " files")
+
+    # The function works fine reading zero files, but this is
+    # probably not what the user wants
+    if(length(files) == 0) warning("No files found")
+
+    x <- lapply(files, function(f) {
+        if(!quiet) message("\t", f)
+        read_parquet(file.path(path, f))
+    })
+    bind_rows(x)
+}
diff --git a/man/read_L1_variable.Rd b/man/read_L1_variable.Rd
new file mode 100644
index 0000000..4f21a11
--- /dev/null
+++ b/man/read_L1_variable.Rd
@@ -0,0 +1,39 @@
+% Generated by roxygen2: do not edit by hand
+% Please edit documentation in R/read_Lx_variable.R
+\name{read_L1_variable}
+\alias{read_L1_variable}
+\title{Read L1 (Level 1) sensor data files}
+\usage{
+read_L1_variable(variable, path, site = NULL, quiet = FALSE)
+}
+\arguments{
+\item{variable}{Variable name ('research name') to be read, character}
+
+\item{path}{Path of the L1 dataset, character}
+
+\item{site}{Optional name of the site(s) of data to read, character}
+
+\item{quiet}{Print diagnostic information? Logical}
+}
+\value{
+A \code{\link[tibble]{tibble}} of L1 data.
+}
+\description{
+This function reads the COMPASS-FME L1 data files (CSV format)
+for a single variable, from one or more sites, and returns
+the compiled data.
+}
+\note{
+This function only works for L1 v2-0 (July 2025) and higher.
+}
+\examples{
+\dontrun{
+read_L1_variable("gw-tds", site = "TMP")
+read_L1_variable("gw-tds", c("TMP", "OWC")) # multiple sites
+read_L1_variable(variable = "gw-tds") # will read all sites' data
+read_L1_variable(variable = "gw-tds", path = "/path/to/L1/data")
+}
+}
+\author{
+BBL
+}
diff --git a/man/read_L2_variable.Rd b/man/read_L2_variable.Rd
new file mode 100644
index 0000000..db29523
--- /dev/null
+++ b/man/read_L2_variable.Rd
@@ -0,0 +1,39 @@
+% Generated by roxygen2: do not edit by hand
+% Please edit documentation in R/read_Lx_variable.R
+\name{read_L2_variable}
+\alias{read_L2_variable}
+\title{Read L2 (Level 2) sensor data files (Parquet format)}
+\usage{
+read_L2_variable(variable, path, site = NULL, quiet = FALSE)
+}
+\arguments{
+\item{variable}{Variable name ('research name') to be read, character}
+
+\item{path}{Path of the L2 dataset, character}
+
+\item{site}{Optional name of the site(s) of data to read, character}
+
+\item{quiet}{Print diagnostic information? Logical}
+}
+\value{
+A \code{\link[tibble]{tibble}} of L2 data.
+}
+\description{
+This function reads the COMPASS-FME L2 data files (Parquet format)
+for a single variable, from one or more sites, and returns
+the compiled data.
+}
+\note{
+This function only works for L2 v2-0 (July 2025) and higher.
+}
+\examples{
+\dontrun{
+read_L2_variable("gw-tds", site = "TMP")
+read_L2_variable("gw-tds", c("TMP", "OWC")) # multiple sites
+read_L2_variable(variable = "gw-tds") # will read all sites' data
+read_L2_variable(variable = "gw-tds", path = "/path/to/L2/data")
+}
+}
+\author{
+BBL
+}
diff --git a/tests/testthat/test-read_Lx.R b/tests/testthat/test-read_Lx.R
new file mode 100644
index 0000000..ad38d37
--- /dev/null
+++ b/tests/testthat/test-read_Lx.R
@@ -0,0 +1,46 @@
+# read_Lx_variable functions
+
+test_that("read_L1_variable works", {
+    # Handles bad input
+    expect_error(read_L1_variable(letters[1:2]), regexp = "Only one variable")
+
+    # Single site
+    x <- read_L1_variable(variable = "gw-tds", path = "./test_data", site = "TMP", quiet = TRUE)
+    expect_s3_class(x, "data.frame")
+    expect_true(all(x$Site == "TMP"))
+
+    # Multiple sites
+    x <- read_L1_variable(variable = "gw-tds", path = "./test_data", quiet = TRUE)
+    expect_s3_class(x, "data.frame")
+    expect_true(length(unique(x$Site)) > 1)
+
+    # Respects quiet flag
+    expect_no_message(read_L1_variable(variable = "gw-tds", path = "./test_data", quiet = TRUE))
+
+    # Warns if no files found
+    expect_warning(read_L1_variable("A", path = "./test_data", quiet = TRUE),
+                   regexp = "No files found")
+})
+
+
+test_that("read_L2_variable works", {
+    # Handles bad input
+    expect_error(read_L2_variable(letters[1:2]), regexp = "Only one variable")
+
+    # Single site
+    x <- read_L2_variable(variable = "sonde-fdom-rfu", path = "./test_data", site = "OWC", quiet = TRUE)
+    expect_s3_class(x, "data.frame")
+    expect_true(all(x$Site == "OWC"))
+
+    # Multiple sites
+    x <- read_L2_variable(variable = "sonde-fdom-rfu", path = "./test_data", quiet = TRUE)
+    expect_s3_class(x, "data.frame")
+    expect_true(length(unique(x$Site)) > 1)
+
+    # Respects quiet flag
+    expect_no_message(read_L2_variable(variable = "sonde-fdom-rfu", path = "./test_data", quiet = TRUE))
+
+    # Warns if no files found
+    expect_warning(read_L2_variable("A", path = "./test_data", quiet = TRUE),
+                   regexp = "No files found")
+})
diff --git a/tests/testthat/test_data/CRC_OW_2024_sonde-fdom-rfu_L2_v2-1.parquet b/tests/testthat/test_data/CRC_OW_2024_sonde-fdom-rfu_L2_v2-1.parquet
new file mode 100644
index 0000000..f7f6987
Binary files /dev/null and b/tests/testthat/test_data/CRC_OW_2024_sonde-fdom-rfu_L2_v2-1.parquet differ
diff --git a/tests/testthat/test_data/OWC_OW_2024_sonde-fdom-rfu_L2_v2-1.parquet b/tests/testthat/test_data/OWC_OW_2024_sonde-fdom-rfu_L2_v2-1.parquet
new file mode 100644
index 0000000..b00b9ec
Binary files /dev/null and b/tests/testthat/test_data/OWC_OW_2024_sonde-fdom-rfu_L2_v2-1.parquet differ
diff --git a/tests/testthat/test_data/OWC_UP_20191120-20191231_gw-tds_L1_v2-1.csv b/tests/testthat/test_data/OWC_UP_20191120-20191231_gw-tds_L1_v2-1.csv
new file mode 100644
index 0000000..848246f
--- /dev/null
+++ b/tests/testthat/test_data/OWC_UP_20191120-20191231_gw-tds_L1_v2-1.csv
@@ -0,0 +1,8 @@
+Site,Plot,TIMESTAMP,Instrument,Instrument_ID,Sensor_ID,Location,Value,research_name,Source_file,F_OOB,F_OOS,F_MAD
+OWC,UP,2019-11-20 09:45:00,AquaTROLL200,683345,,,0,gw-tds,00a8b042,,0,
+OWC,UP,2019-11-20 09:45:00,AquaTROLL200,683345,,,0,gw-tds,14554582,,0,
+OWC,UP,2019-11-20 09:45:00,AquaTROLL600,685474,,,0,gw-tds,aa6819aa,,0,
+OWC,UP,2019-11-20 09:45:00,AquaTROLL600,685474,,,0,gw-tds,ed26e520,,0,
+OWC,UP,2019-11-20 10:00:00,AquaTROLL200,683416,,,0,gw-tds,ef1bae45,,0,
+OWC,UP,2019-11-20 10:00:00,AquaTROLL200,683345,,,0,gw-tds,00a8b042,,0,
+OWC,UP,2019-11-20 10:00:00,AquaTROLL200,683345,,,0,gw-tds,14554582,,0,
diff --git a/tests/testthat/test_data/TMP_F_20191120-20191231_gw-tds_L1_v2-1.csv b/tests/testthat/test_data/TMP_F_20191120-20191231_gw-tds_L1_v2-1.csv
new file mode 100644
index 0000000..3bde961
--- /dev/null
+++ b/tests/testthat/test_data/TMP_F_20191120-20191231_gw-tds_L1_v2-1.csv
@@ -0,0 +1,8 @@
+"Site","Plot","TIMESTAMP","Instrument","Instrument_ID","Sensor_ID","Location","Value","research_name","Source_file","F_OOB","F_OOS","F_MAD"
+"TMP","F","2019-11-20 09:45:00","AquaTROLL200","683345",,,0,"gw-tds","00a8b042",,0,
+"TMP","F","2019-11-20 09:45:00","AquaTROLL200","683345",,,0,"gw-tds","14554582",,0,
+"TMP","F","2019-11-20 09:45:00","AquaTROLL600","685474",,,0,"gw-tds","aa6819aa",,0,
+"TMP","F","2019-11-20 09:45:00","AquaTROLL600","685474",,,0,"gw-tds","ed26e520",,0,
+"TMP","F","2019-11-20 10:00:00","AquaTROLL200","683416",,,0,"gw-tds","ef1bae45",,0,
+"TMP","F","2019-11-20 10:00:00","AquaTROLL200","683345",,,0,"gw-tds","00a8b042",,0,
+"TMP","F","2019-11-20 10:00:00","AquaTROLL200","683345",,,0,"gw-tds","14554582",,0,