diff --git a/src/lib/aws.ts b/src/lib/aws.ts
index ac06c9d..6aabf4b 100644
--- a/src/lib/aws.ts
+++ b/src/lib/aws.ts
@@ -19,6 +19,7 @@ import {
     GetResourcesCommandOutput,
     ResourceGroupsTaggingAPIClient,
 } from '@aws-sdk/client-resource-groups-tagging-api'
+import { ensureValueWithExchange } from './utils'
 
 export const RUN_ID_TAG_KEY = 'runId'
 export const TITLE_TAG_KEY = 'title'
@@ -46,7 +47,7 @@ export async function registerECSTaskDefinition(
     // The following defines a new family versus versioning the base family
 
     const containerDefinition = baseTaskDefinition.containerDefinitions?.map((container) => {
-        const environment = container.environment || []
+        const environment = ensureValueWithExchange(container.environment, [])
 
         environment.push({
             name: 'TRUSTED_OUTPUT_ENDPOINT',
diff --git a/src/lib/run-studies.ts b/src/lib/run-studies.ts
index 4cad448..8973a15 100644
--- a/src/lib/run-studies.ts
+++ b/src/lib/run-studies.ts
@@ -11,7 +11,7 @@ import {
     getTaskDefinitionsWithRunId,
     deleteECSTaskDefinitions,
 } from './aws'
-import { filterManagementAppRuns, filterOrphanTaskDefinitions } from './utils'
+import { ensureValueWithExchange, ensureValueWithError, filterManagementAppRuns, filterOrphanTaskDefinitions } from './utils'
 import { managementAppGetRunnableStudiesRequest, toaGetRunsRequest } from './api'
 import 'dotenv/config'
 import { ManagementAppGetRunnableStudiesResponse } from './types'
@@ -32,10 +32,10 @@ async function launchStudy(
         { key: TITLE_TAG_KEY, value: studyTitle },
     ]
     const baseTaskDefinitionData = await getECSTaskDefinition(client, baseTaskDefinition)
-
-    if (baseTaskDefinitionData.taskDefinition === undefined) {
-        throw new Error(`Could not find task definition data for ${baseTaskDefinition}`)
-    }
+    baseTaskDefinitionData.taskDefinition = ensureValueWithError(
+        baseTaskDefinitionData.taskDefinition,
+        `Could not find task definition data for ${baseTaskDefinition}`,
+    )
 
     const newTaskDefinitionFamily = `${baseTaskDefinitionData.taskDefinition.family}-${runId}`
 
@@ -47,10 +47,14 @@ async function launchStudy(
         imageLocation,
         taskTags,
     )
-
-    if (registerTaskDefResponse.taskDefinition?.family === undefined) {
-        throw new Error('Generated task definition has undefined family')
-    }
+    registerTaskDefResponse.taskDefinition = ensureValueWithError(
+        registerTaskDefResponse.taskDefinition,
+        `Could not register task definition ${newTaskDefinitionFamily}`,
+    )
+    registerTaskDefResponse.taskDefinition.family = ensureValueWithError(
+        registerTaskDefResponse.taskDefinition.family,
+        'Generated task definition has undefined family',
+    )
 
     return await runECSFargateTask(
         client,
@@ -78,7 +82,10 @@ async function cleanupTaskDefs(
     ecsClient: ECSClient,
 ) {
     // Garbage collect orphan task definitions
-    const taskDefsWithRunId = (await getTaskDefinitionsWithRunId(taggingClient)).ResourceTagMappingList || []
+    const taskDefsWithRunId = ensureValueWithExchange(
+        (await getTaskDefinitionsWithRunId(taggingClient)).ResourceTagMappingList,
+        [],
+    )
     const orphanTaskDefinitions = filterOrphanTaskDefinitions(bmaResults, taskDefsWithRunId)
     await deleteECSTaskDefinitions(ecsClient, orphanTaskDefinitions)
 }
@@ -88,10 +95,10 @@ export async function runStudies(options: { ignoreAWSRuns: boolean }): Promise<v
     const taggingClient = new ResourceGroupsTaggingAPIClient()
 
     // Set in IaC
-    const cluster = process.env.ECS_CLUSTER || ''
-    const baseTaskDefinition = process.env.BASE_TASK_DEFINITION_FAMILY || ''
-    const subnets = process.env.VPC_SUBNETS || ''
-    const securityGroup = process.env.SECURITY_GROUP || ''
+    const cluster = ensureValueWithExchange(process.env.ECS_CLUSTER, '')
+    const baseTaskDefinition = ensureValueWithExchange(process.env.BASE_TASK_DEFINITION_FAMILY, '')
+    const subnets = ensureValueWithExchange(process.env.VPC_SUBNETS, '')
+    const securityGroup = ensureValueWithExchange(process.env.SECURITY_GROUP, '')
 
     const bmaRunnablesResults = await managementAppGetRunnableStudiesRequest()
     const toaGetRunsResult = await toaGetRunsRequest()
diff --git a/src/lib/utils.test.ts b/src/lib/utils.test.ts
index 25e02de..18df7c1 100644
--- a/src/lib/utils.test.ts
+++ b/src/lib/utils.test.ts
@@ -1,5 +1,5 @@
 import { describe, it, expect, beforeEach, vi } from 'vitest'
-import { filterManagementAppRuns, filterOrphanTaskDefinitions } from '../lib/utils'
+import { filterManagementAppRuns, filterOrphanTaskDefinitions, ensureValueWithError, ensureValueWithExchange } from '../lib/utils'
 
 describe('filterManagementAppRuns', () => {
     it('filters out runs in the TOA', () => {
@@ -91,3 +91,29 @@ describe('filterOrphanTaskDefinitions', () => {
         expect(filterOrphanTaskDefinitions(mockManagementAppResponse, mockTaskDefResources)).toStrictEqual(['arn2'])
     })
 })
+
+describe('ensureValueWithError', () => {
+    it('makes sure values are defined', () => {
+        expect(ensureValueWithError(10)).toBe(10)
+    })
+
+    it('responds with the given error message if values are undefined', () => {
+        expect(() => ensureValueWithError(null, "Can't be null or undefined")).toThrowError("Can't be null or undefined")
+        expect(() => ensureValueWithError(undefined)).toThrowError()
+    })
+})
+
+describe('ensureValueWithExchange', () => {
+    it('makes sure values are defined', () => {
+        const myValue: number | undefined = 10
+        expect(ensureValueWithExchange(myValue, 0)).toBe(10)
+    })
+
+    it('exchanges the value if undefined', () => {
+        const myObject: { myStringArray: string[] | undefined; myNumber: number } = {
+            myStringArray: undefined,
+            myNumber: 10,
+        }
+        expect(ensureValueWithExchange(myObject.myStringArray, ['my string'])).toEqual(['my string'])
+    })
+})
diff --git a/src/lib/utils.ts b/src/lib/utils.ts
index 9e2bf86..70ae68c 100644
--- a/src/lib/utils.ts
+++ b/src/lib/utils.ts
@@ -35,3 +35,19 @@ export const filterOrphanTaskDefinitions = (
 
     return orphanTaskDefinitions
 }
+
+// returns given value with type certainty, or errors if value is null or undefined
+export const ensureValueWithError = <T>(value: T, message?: string): NonNullable<T> => {
+    if (value === null || value === undefined) {
+        throw new Error(message)
+    }
+    return value
+}
+
+// returns given value with type certainty, or silently exchanges value if null or undefined
+export const ensureValueWithExchange = <T>(value: T, exchange: NonNullable<T>): NonNullable<T> => {
+    if (value === null || value === undefined) {
+        return exchange
+    }
+    return value
+}